Expansile pseudotumor of reactive hemorrhagic tissue arising in bone
- characterised by blood filled spaces separated by fibrous tissue
Primary 50%
- arise de novo
Secondary 50%
- in association with other tumours
- probably secondary to haemorrhage into 1° tumour
- GCT / chondroblastoma / osteoblastoma / osteosarcoma
- often only small component
- should treat as underlying 1° tumour
Metaphysis of long bones
- proximal humerus
- femur
- tibia
Posterior elements of vertebra
Teenagers
- 80% occur in 10-20 year range
F>M
Pathological fracture rare
May resolve with fracture or skeletal maturity
Multi-loculated lesion
- eccentric
- expansile
- cortical thinning
Usually increased uptake
- centre may have decreased uptake
Exclude polyostotic disease
Haemosiderin content
- low to intermediate signal on T1 and T2
Fluid - Fluid levels
- due to sedimentation of RBC's & serum within the cavities
- patient must remain motionless for 10 minutes prior to the scan being performed
- allows time for sedimentation
Fibrous dysplasia
GCT
ABC
Infection
Unicameral Bone Cyst
Osteosarcoma
Gross
Blood filled spaces with fibrous septa
Histology
Cells
- haemosiderin-laden macrophages
- multinucleated giant cells
Septa
- fibrous stroma
- small amounts of osteoid
Can observe majority
- need to avoid contact sports
Biopsy / diagnose
Potential instability - proximal femur / spine
Pain
Recurrent fracture / debilitating
Currettage and bone graft
Allograft / Joint Replacement
Embolisation
Sclerotherapy
Concept
Principles of biopsy approach
- confirm diagnosis on frozen section
- proceed to treatment
Indication
Must be able to preserve articular surface
Technique
Full and careful curettage
- intra-lesional treatment
- need to burr away all of lesion
- must take care as bone very thin
- areas of fracture not uncommon
- must beware growth plates in skeletally immature
- supplement with bone graft / bone marrow aspirate / PMMA
Indications
Articular cartilage not salvageable
Indications
- preoperative in spine lesions
Results
Rossi et al Skeletal Radiol 2010
- 55 cases both spine and appedicular with N butyl cryanoacrylate
- successful in 94% cases
- a second (25%) and third (14%) embolisation required
- 2 cases of skin necrosis and one transient paresis
Results
Rastogi et al JBJS Br 2006
- percutaneous sclerotherapy with polidocanol in 72 patients under II guidance
- all had histological diagnosis prior to treatment
- 84.5% clinical response
- required between 1 and 5 treatments (average 3)
- 2 recurrences successfully treated with repeat sclerotherapy
Varshney et al Clin Orthop Relat Research 2010
- RCT of sclerotherapy v intralesional resection of 94 ABCs
- 3 year follow up
- 93% healing in sclerotherapy group with minimal complications
- 84% healing in operative group with 3 deep and 5 superficial infections and 2 growth disturbances
Papagelopoulos et al Spine 1998
- 52 cases in the spine
- treated with extralesional and intralesional excision with bone grafting
- 10% recurrence at 10 years, all presenting within 6 months post surgery
- 4 patients had postoperative radiotherapy
- 1 died of radiation related osteosarcoma, 1 of intraoperative bleeding
- now recommend preoperative embolisation
Rare low-grade malignant tumour
- cell of origin unknown
Usually second or third decade of life
90% diaphysis of tibia
Mandible
Most common anterior cortex of tibia
Soap-bubble appearance
Eccentrically located
- well circumscribed
- slightly expansile
- cortical thickening
- little or no periosteal reaction
- can have late deformity
Fibrous dyplasia
Osteofibrous dysplasia / Ossifying fibroma / Osteosarcoma
Giant cell tumour
ABC
Chondrosarcoma / CS
Infection / osteomyelitis
Unicameral bone cyst
Diaphyseal lesion / HALFEE
- Histiocytoma
- Adamantinoma
- leukemia
- FD
- EG
- Ewings
Two distinctly different components
1. Epithelial origin
- composed of squamous cells and epithelial pearls
2. Mesenchymal origin
- composed of immature mesenchymal cells and spicules of dysplastic bone
- closely resembles the pattern of fibrous dysplasia and its variant ossifying fibroma
Adamantinoma is considered by some to be a malignant variant of fibrous dysplasia
- resemblance of the mesenchymal component to fibrous dysplasia / ossifying fibroma
- the presence of the epithelial component makes adamantinoma a distinctly different entity
Intra-osseous, intra-cortical Stage 1A Osteosarcoma
Metastasis in 20% of cases
Biopsy followed by wide resection
- chemo and radiotherapy ineffective
- need to address bone loss
- vascularised fibular graft / allograft / bone transport
Qureshi et al JBJS Am 2000
- multicentred retrospective review of 70 cases
- average age 31, more common in males
- limb salvage attempted in 91% and successful in 84%
- up to 50% complication rate with limb reconstruction (fracture, non union)
- wide operative margins associated with lower recurrence rates
- 87% 10 year survival
Older patients
- eipiphysis / diaphysis of long bones usually
Lytic lesion with sclerotic rim
Benign
- foam cells
- lipid filled cells
Curette and bone graft
- chance of recurrence
Rare cartilage tumour
1% of bone tumours / rare
- typically in adolescents
Usually benign
- but aggressive / frankly malignant behaviour reported
- locally aggressive
- can have pulmonary metastasis
Arises in secondary ossification centre / epiphysis
- proximal tibia / knee
- proximal femur / hip
Develops < physis closes (unlike GCT)
Usually painful
- may produce limitation of joint ROM
May produce altered epiphyseal growth in young children
Eccentric epiphyseal
- well-defined lucency
- thin sclerotic reactive rim
Often internal stippled calcification
- popcorn or chicken wire calcification in 25%
- ± metaphyseal periosteal reaction
Rarely diagnostic
- many tumours will have areas of hemorrhage
- causes high signal intensity on T2
- i.e. GCT / ABC / chondroblastoma
Histology
Stage 2 lesion typically / benign active
- active / intracapsular but with aggressive stroma
Sheets of chondroblasts and amorphous cartilage
- polygonal cells
- bluish cytoplasm
- cobblestone appearance of fine surrounding calcium like "chicken wire"
- occasional giant cells
Atypical cartilage matrix
- stain +ve for S100
- chondroid Matrix
Epiphyseal lesion in adults
- chondroblastoma
- GCT
- clear cell chondrosarcoma
- infection
- telangiectatic osteosarcoma
- difficult to eradicate due to anatomic position without damaging joint or physis
- i.e. located in hip and knee close to joint surface
1. Currettage and bone graft
2. Radiofrequency ablation
3. Wide excision / usually necessitate allograft reconstruction or joint replacement
Technique
- intra-articular exposure required
- meticulous debridement with burr
- local adjuvant treatment - Phenol / Liquid N2
- avoid damage to physis
- allograft / autograft / PMMA
Problem
- may not be possible to prevent injury to joint due to location
Recurrence
More common in femur and foot/ankle
- should have CT chest to exclude pulmonary metastasis
- can be cured by second currettage
Results
Sallhan et al JBJS Am 2009
- retrospective review of 87 cases
- 32% recurrence by 24 months
- most likely with epiphyseal lesions
Ramappa et al JBJS Am 2000
- 73 patients treateed with 15% local recurrence
- 1 patient recurred 3 times
- one patient died of metastasis
- one patient was cured of metastasis by aggressive surgery
Results
Rybak et al Radiology 2009
- 14 patients treated and available for follow up
- 12 had good relief of symptoms with no further treatment required
- 1 patient required repeat treatment
- 1 patient had collapse of chondral surface with residual tumour
Indication
- usually requires resection / reconstruction of joint
- indicated for second recurrence
Pulmonary metastasis
- resect if possible
Benign neoplasm of cartilaginous origin composed primarily of myxoid cartilage
Previously thought to be Chondrosarcoma
Very rare tumour
- young adults 10-30
- M:F 2:1
Common upper tibia
- metaphysis of long bones
- lower limb predilection
Tenderness
Local bulge
Eccentrically placed metaphysis
- round or oval lucency
- well-defined sclerotic margin
- local expansion but cortex intact
- erodes / balloons the cortex
- characteristic buttress of periosteal new bone formation
Indistinguishable from an ABC
Lobulated areas of spindle shaped stellate cells
- abundant myxoid / chondroid intercellular material
- multinucleated giant Cells
- merging of benign elements - hyaline cartilage / myxoid tissue / fibrous tissue
ABC
Fibrous cortical defect
Fibrous Dysplasia
Intra-lesional curettage & bone grafting
- recurrence common (40%)
- treat with wide resection
If Stage 3 lesion consider marginal or wide resection
Langerhan's Cell Histiocytosis
- non-neoplastic disorder
- characterised by infiltration by histiocytic cells (Monocyte / macrophage lineage)
Group of granulomatous inflammatory processes of unknown aetiology
- involve the reticuloendothelial component of the bone marrow, parenchymal organs, and skin
E - H - L
- 5-20 years
- only manifestation is Osseous
- one or more lesions
2. Hand-Schuller-Christian Disease (20%)
Think of as multiple EG's
- more widespread granulomas
- systemic manifestation of EG
Classically triad of
- diabetes insipidus (parapituitary involvement)
- exopthalmos (orbital involvement)
- skull defects
Plus
- osseous lesions with mild to moderate visceral involvement
- lymphadenopathy
- hepatosplenomegaly both from EG
- skin lesions
- pulmonary disease
Less aggressive than LS
- 10% die
3. Letterer-Siwe Disease (10%)
- often infants < 1
- probably unrelated neoplastic condition
- rare disseminated disease of infants with fulminant course
- major visceral involvement: RES, pulmonary, anaemia
- death from hepatic failure
- less osseous involvement
Unknown
Cell of origin is Langerhan's Cell
- ? immunoregulation disorder
- deficiency of Suppressor T-Cells
- uncontrolled macrophage proliferation
Eosinophilic Granuloma (70%)
- affects children age 4-7 years
- presentation variable & non specific
Back pain from vertebral lesion (most common presentation)
Localised swelling (especially Skull)
Pain, limp & muscle wasting with pelvic or leg EG
- pathological fracture
Any bone may be affected
- skull / spine / femur / flat bones (ribs, pelvis)
Less common in long bones
- diaphyseal
- solitary lesion in 50%
- if multiple, < 3 lesions
Inconsistent & moderate elevation of ESR + anaemia
1. Vertebra Plana
- compression of body
- vertebral body widened
- usually involves end plate rather than neural arch
- discs intact
DDx
- Ewings
- MM, Mets, Lymphoma, Leukaemia
- ABC
- infection
2. Long Bones
Diaphyseal osteolytic lesion
- thin sclerotic rim with endosteal scalloping
- cortical expansion with overlying periosteal reaction
- appearances vary according to stage of healing
DDx
- HALFEE
3. Skull
- most common site
- multiple punched out lucencies
- coalesce to give geographic skull
- typically bevelled edge appearance to lesion
Lesion is low signal on T1 & high signal on T2
- enhancing brightly with gadolinium (good discriminator)
Need to rule out HSCD or LS
- bone scan & skeletal survey
Defect filled with lipid-laden histiocytes with eosinophilic cytoplasm
- plasma cells (blue with cartwheel nucleus)
- eosinophils (pink with bilobed nucleus)
- plasma cells with occasional eosinophils
Cytoplasm of cells contains specific Inclusion X bodies
- same as Birbeck granules in Langerhans Cell
- visible under EM
Positive staining for S100
Usually self-limiting
- fibroblasts obliterate histiocytes & inflammatory response
- tissue replaced by bone
- self limiting
- will resolve
- no treatment required
- symptomatic
- progressive
- neurological deficit
- at risk of pathological fracture
1. Intralesional steroid
Rimondi et al Skeletal Radiol 2009
- CT guided percutaneous intralesional methylprednisone
- success in 17/19 patients
- remaining two found to have systemic disease
Yasko et al JBJS Am
- 35 lesions
- resolution in all but one
- 97% success
2. Curettage and bone grafting
Systemic treament / chemotherapy
- radiotherapy for localised lesions
- alkylating agents + steroids
- poor results if recurrence within 1 year
Non Ossifying Fibroma
A hamartomatous defect in the metaphyseal cortex of skeletally-immature adolescents
Fibrous cortical defect
- < 2cm in diameter
Non ossifying fibromas
- > 2cm
Localised defect in cortex of long bone
- failure of bone to form
Most common skeletal lesion
- 35% of young children
- most common cause of pathological fracture in children
Self limiting
- usually ossify by early adulthood
- ? become bone islands
Distal femur
Distal tibia
Child
- incidental finding
- pathological fracture
Non-Ossifying Fibroma
- > 2 cm
- eccentric metaphyseal lesion
- sclerotic margin
- slight expansion of cortex
- usually < 1/3 diameter of bone
Fibrous Cortical Defect
- < 2cm
- small cortical lucency
- sharply defined border
Fibroblasts in whorling fibrous stroma
- multinucleated giant cells
- no bone formation
Usually don't require biopsy
- biopsy if uncertain
Management
Serial observation
- xray yearly
- 35% of children have them
Indication for surgery
- large lesions
- > 1/2 diameter of bone
Management
- curettage & bone graft
Management
1. Treat closed if possible
- fracture heals in normal length of time
- lesion may heal with fracture union
2. If persists, curettage / graft
Developmental hamartoma in which areas of the skeleton fail to mature normally
- remain indefinitely as immature, poorly mineralized trabeculae
Hamartoma of bone and fibrous tissue
Rare triad of
1. Fibrous Dysplasia
2. Cafe-au-Lait Spots
- irregular 'Coast of Maine'
- compare with regular outline of 'Coast of California' in NF
3. Precocious puberty
Monostotic 0.4%
Polyostotic / Albright's 4%
- OS / FS / CS
Usually non genetic inheritance
Only Tibia
- precursor Adamantinoma
- more dense with trabecular pattern
- plump rimming osteoblasts
1. Monostotic 85%
2. Polyostotic 15%
3. Associated with endocrinopathy
- Vit D Resistant Rickets
- Hyperthyroidism
- DM
- Acromegaly
- Cushing' s syndrome
Any bone
Femur
- involved in 90% polyostotic
Tibia
Skull / maxilla / ribs
Usually diagnosed in children and adolescents
Remains relatively unchanged throughout life
- in keeping with developmental abnormality
Monostotic
- incidental finding
Polyostotic
- usually present in childhood
- pain (indicates microfracture)
- pathological fracture
- limp
- deformity
Intramedullary diaphyseal lesion
- 'ground glass appearance'
- tissue that is more lucent with a similar to the density of cancellous bone
- homogeneous with no visible trabecular pattern
Thinned, slightly bulged cortex
- ± endosteal scalloping
± Angular deformity at site of lesion
Coxa vara of proximal femur
- Shepherd's Crook deformity
- secondary LLD
Sabre tibia
Skeletal Survey
- mono v polyostotic
- look for other lesions
Low T1 SI
Low - High T2 SI
"Chinese letters"
- strands of osteoid & bone arising from fibrous stroma
- irregularly shaped bony trabeculae in fibrous stroma
Basic rule is don't operate unless deformity
Any morcellised bone graft is resorbed
Guille et al JBJS Am 1998
- 100% resorption of bone graft with recurrence of lesion
- osteotomy and fixation with reconstruction nail mainstay of treatment
Bisphosphonates
- to relieve pain
Results
Chapuriat et al Bone 2004
- marked reduction in pain
- some resolution / filling in of lesions
Aim
- stabilise diaphysis
- prevent coxa vara
- try to wait until skeletal maturity
Management
1. Valgising osteotomy
2. Plate (immature) / Reconstruction Nail (mature)
Results
Yang et al Acta Orthop Trauma Surg 2010
- 14 cases with valus osteotomy / currettage / allograft and reconstruction nail
- good restoration of alignment with improvement in LLD
- no recurrent fractures or progression of deformity
Management
Osteotomy + IM nail
Beware large cysts
Benign lesion with a wide spectrum of behavior characterized by stromal cells and giant cells
Common
- 20% of benign tumours
More common females
- F:M = 1.5:1
- most tumours M>F
Usually patient in 20's
- usually after skeletal maturity
- 3% < epiphyseal closure
Can behave in malignant fashion
Epiphysis
Knee 50%
- distal femur
- proximal tibia
Remainder
- distal radius
- sacrum
- vertebral bodies (anteriorly like EG compared with ABC/OO)
Involved joint has
- dull ache
- effusion
- muscle atrophy
Pathological fracture common
Well-defined defect in epiphysis & metaphysis
- no sclerosis around lesion
- sub-articular with extension into subchondral bone
May extend into articular cartilage
- unique ability
Minimal periosteal reaction
± Cortical breach & soft tissue extension
Brown's tumour / hyperparathyroidism
Show cortical destruction & soft tissue extension
- soft tissue extension suggest stage 3 aggressive
Mono v polyostotic
Ca++ / Se PO4
- rule out Brown's tumour
ESR
- Osteomyelitis & EG
Two Cell Types
A Multinucleated Giant Cells
- similar to osteoclasts
- likely reactive
B. Small Stromal Cells
- ? the actual tumour
- probably osteoblast derivatives
Background of fibrous tissue
- normal mitoses usually seen
- areas of spontaneous necrosis (rare for benign tumours)
- thin cortical shell
Stage I Latent (15%)
Sclerotic Rim
- asymptomatic
- inactive on bone scan
- histologically benign
Stage II Active (70%)
Expanded cortex but no breakthrough
- symptomatic
- often have pathological fracture
- active on bone scan
- histologically benign stromal cells
Stage III Aggressive (15%)
Rapidly growing mass
- cortical perforation with ST mass
- symptomatic
- extensive activity on bone scan
- histologically benign
Malignant
- rare form
- sarcomatous lesion contiguous with benign GCT
Previously said 10% metastasize
- many of these would now be called MFH
- for it truly to be giant cell have to see typical appearance of GCT in metastasis
Primary malignant GCT better prognosis than malignant change in recurrence
ABC / UBC
Chondroblastoma
Clear cell sarcoma
Telangiectatic Osteosarcoma
Synovial cyst of OA / Geode
PVNS
OM (brodies abscess)
Because there are 2 malignant tumours which can mimic
- all need careful staging and biopsy
Biopsy usually performed
1. Currettage + bone graft / PMMA
2. Wide excision + allograft / arthroplasty
3. Adjuvant treatment
Management
Currettage and PMMA
- extended curette with high speed burr
- saucerisation
- bone graft under subchondral bone
- adjuvant PMMA (works by thermal necrosis)
Results
Blackley et al JBJS Am 1999
- treatment of 59 patients with high speed burr and autograft / allograft
- 12% local recurrence
Becker et al JBJS Am 2008
- demonstrated reduced local recurrence with the use of PMMA
Bauer et al JBJS Br 2006
- treatment of recurrences with repeat currettage and PMMA
- 13/15 successful after one treatment, remainder after 2
Management
Wide resection & osteochondral allograft / arthroplasty + adjuvant DXRT
Indications
- extensive soft tissue tumour
- extensive cortical destruction / pathological fracture
- joint destruction
Results
Bell et al J Arthroplasty 1994
- fresh osteochondral allograft for distal femur in 16 patients
- 3 revisions and 1 late infection
- 8/13 assessed were good or excellent
DXRT
- i.e. sacral and pelvic GCT
Theory
GCT rich in osteoclast derived cells
Results
Balke et al BMC 2010
- use of bisphosphonates in aggressive primary / recurrent / metastatic GCT
- no increase in size in inoperable tumours
- no recurrences in tumours that had repeatedly recurred
- lung metastasis did not increase in size or number
Enneking
- grade 1 = negligible recurrence
- grade 2 = 20%
- grade 3 = 70%
- grade 3 + adjuvant = 20%
Lung metastases occur in 2%
- lesions slowly progress ie benign in nature
- usually treat with surgical resection
- consider GCT benign if pulmonary metatasis histologically benign
- regular CXR in patients with GCT
Hamartomatous proliferation of vascular tissue
Commonest tumours in infancy & childhood
- usually superficial
Capillary
- majority
- small nodules of capillary sized vessels lined by flattened endothelium
- nodules clumped in lobular pattern
Cavernous
- less common
- usually larger & involve deeper structures
1. Klippel Trenaunay Weber Syndrome
- hemihypertrophy with underlying venous malformations
- secondary to increased angiogenesis
- UL, LL or both affected
- usually unilateral
2. Maffucci Syndrome
3. Sturge-Weber
- rare congenital / not hereditary
- often facial capillary malformation
- more extensive hemangiomata
- mental retardation / seizures / hemiparesis
- hemiatrophy
Cutaneous
Subcutaneous
Intramuscular
Intra-osseous
Ache
Limb heaviness
Lesions in the skin - distended bluish discoloration
Deeper intramuscular lesions present as a tender mass
Soft-tissue lesions
- same radiodensity of muscle
Often small calcified nodules / phleboliths
- circular pattern with a radiolucent center (due to recanalization)
- same as those seen in the pelvic veins of multiparous females
Exceedingly bright signal
- due to the high fluid content of the lesion
Polka dot appearance due to section through the vessels
These lesions often penetrate the bone and have a large soft tissue component
As pain / disability demands
- often observation
Non-operative
- stockings
- simple analgesia
Operative
- resection
- embolization
Beware rare cases of malignant change
Epidemiology
- F:M = 2:1
- incidence increases with age
- 0.8% of 1° bone tumours
- commonest sites are spine (especially thoracic) & skull
X-ray
Characteristic finding is the coarsened vertical trabeculae
Spine
- honeycomb or corduroy cloth appearance
- in spine this finding is usually sufficient for the diagnosis
Skull
- spoke-wheel configuration
CT
Characteristic finding is multiple dots "polka dots"
MRI
Usually bright on T1 & T2 images because of fat content
- areas of trabecular thickening will have low signal intensity
Congenital hamartomatous lesion
- occurs almost exclusively in the tibia or mandible
- striking resemblance to fibrous dysplasia
- thought by many to be a variant of that condition
Anterior cortex of tibial diaphysis
Mandible
Young child
Anterior bow or mass in tibia
Pathological fracture common
Multiple small radiolucent lesions
Rim of reactive bone
Adamantinoma
Fibrous Dysplasia
EG
Ewing's
Periosteal OS
Issue
Risk of adamantinoma in lesion
- recommended excision of all lesions
Currettage alone
- 100% recurrence rate
Results
Lee et al JBJS Br 2000
- review of 16 patients with osteofibrous dysplasia tibia
- 6 treated initially with currettage / all recurred
- treated with segmental excision and management of bone defect
- some small lesions
- others requiring fibular graft or bone transport
- 3 confirmed cases of adamantinoma
- no recurrences
- recommend excision in all cases
Metaphyseal Enchondroma
Arise from the metaphyseal cortex of long bones
- most common in the proximal humerus
Difficult to DDx from Chondrosarcoma
Masses of cartilage nestling in a shallow crater in the periphery of the cortex
Don't ossify
- remain as immature cartilage
No malignant potential
- Don't transform into CS
Juxta-cortical chondrosarcoma
Periosteal osteosarcoma
Simple Bone Cyst
A simple bone cyst is a solitary cavity containing clear fluid
- originating in the metaphysis of growing children
- adjacent to the metaphyseal aspect of the growth plate.
Unknown pathological origin
- likely secondary to venous obstruction / hypertension
- probably not neoplastic
- occurs during growth
Children
M 2:1
Proximal metaphysis
- humerus 67%
- femur 15%
Often immediately below physis
- metaphyseal side
Can occur in os calcis
Active
- adjacent to physis
Latent
- separated from physis by normal bone
Present with pain caused by pathological fracture
- commonest presentation 75%
Metaphyseal near physis
- well-defined lucency
- thin sclerotic rim
- usually central
- thinned cortex with slight expansion
- thin internal septa
- can be multi-loculated
Fallen-Leaf sign
- with pathological fracture
- "Classic" sign
- pathognomonic because indicates that the lesion has no matrix & is fluid filled
DDx ABC
ABC
- eccentric (v central)
- width > physis
- can be very difficult to tell
Pressure
- they have an arteriolar pressure curve
- cyst pressure is higher than venous pressure
Fluids
- contain high levels of prostaglandins
- contain high levels of alkaline phosphatase
Gross
Thin cyst lining with fine septae
- contains clear fluid compared with ABC
Histology
Thin fibrous layer of CT
- cells resembles synovial cells
- few multinucleated giant cells
Tend to become latent
- resolve in adulthood
- may resolve post fracture
Will eventually heal, but tend to fracture up to 4 times on average
1. Humerus
- fractures will heal in sling
- must then avoid non contact sports
- difficult to tell child not to play sports for many years
2. Femur
- want to prevent fracture
- avoid morbidity / deformity
Observe
Inject HCLA
Inject bone marrow aspirate
Currettage and bone graft
Cyst drainage
- cannulated screws
- IM rods
ORIF
Inactive & small
Technique
Aspirate initially
- if aspirate blood / treat as ABC / biopsy
- if aspirate fluid / simple cyst
Inject contrast
- ensure not loculated
- if it is, need to inject all parts of cyst
Inject methylprednisolone
- steroid blocks PGE
- methylprednisolone 50 - 200mg
- second needle as vent
Results
Rud et al Orthopaedics 1991
- 11 UBC treated with injection of methyprednisolone
- 2 required second treatment
- 5 cysts resolved completely whilst 6 resolved sufficiently that fracture was no longer a risk
Technique
GA / Aspirate from bone marrow
- inject into cyst under II
Results
Rougraff et al JBJS Am 2002
- 25 cases treated with percutaneous bone marrow aspirate
- combined with demineralised bone matrix
- 5 recurrences
Wright et al JBJS Am 2008
- RCT of bone marrow aspirate v HCLA in 77 patients followed for 2 years
- 42% in the methylpredisolone group healed
- 23% in the bone marrow group healed
Results
Hunt Orthopedics etal 2009
- 21 proximal humeral cysts
- 75% union rate
Concept
- venous hypertension cause of cyst
- if allow cyst to drain, will heal
Options
- cannulated screw into lesion
- TENS nails humerus
- IMN femur
Results
Linhart et al Orthopedics and Traumatology
- 21 proximal humeral cysts
- distal to proximal flexible nails
- 95% union rate
Hou et al JBJS Am 2010
- humeral cysts
- 11/12 healing with currettage / synthetic bone graft / cannulated screw
Treat fractures non operatively in sling initially
- need treatment if debilitating
Options
1. Non operative / avoid contact sports and wait
2. Injection HCLA
- minimally invasive, perform in OT
3. Percutaneous TENS nails
Pathological fracture
- treat in traction / spica if minimally displaced or very young
- otherwise paediatric sliding hip screw
- reconstruction nail if > 15 years
Non fractured but high risk
- trial injection
- paediatric hip screw if < 15 with bone grafting
- IMN if > 15
In caisson workers / divers
Sickle cell anemia
Long term steroid
May sometimes be a degenerating lipoma of bone
Chondroblastoma / Chondrosarcoma
- if in metaphyseal region
Enchondroma
Bone island
No increased uptake
Mineralisation of necrotic marrow elements
MFH may arise from long standing bone infarcts
Benign intramedullary cartilage lesion
Enchondroma are presumed to be remnants of hyaline cartilage
- derived from the epiphyseal growth mechanism that failed to undergo enchondral ossification
10% of benign bone tumours
Young adults
Stop growing in adults and calcify
Rare
- enchondroma in hands and feet always benign
- benign looking enchondroma located centrally may be malignant
Age
- in general not malignant prior to maturity
Bone scan not helpful
Histology not helpful
Intramedullary
Start near physis (metaphyseal) but may become diaphyseal
Involves any bone formed by endochondral ossification
- especially tubular bones of hands & feet
- 50% in hands, especially phalanges
- 10% in feet
- also common femur, humerus & ribs
Can have periosteal chondroma
- surface long bones
- calcified matrix
- well demarcated cortical defect
Usually incidental finding
- may be patholological finding
Intralesional calcification in adults
- especially in long bones
- punctate, stippled calcification and broken rings
No periosteal reaction
1. X-ray appearance
- scalloping (endosteal erosion)
- periosteal reaction
- fluffy calcification
2. Size > 6-10 cm rarely benign
3. Peripheral vs central
- central pelvis / shoulder girdle more concerning
4. Age - malignancy rare <20
5. Solitary vs Olliers
- benign more cellular in Olliers
Usually increased uptake
Composed of masses of hyaline cartilage without characteristic architecture
- typically bland cartilage
- no pleomorphism / anaplasia / hyperchromasia
- hand lesions tend to look more hypercellular & pleomorphic
Can be very difficult to distinguish between low grade chondrosarcoma and enchondroma
Long Bone with Intralesional Calcification
1. Enchondroma
2. Bone infarct
3. Chondrosarcoma
Phalanx
- epidermoid inclusion cyst
- glomus tumour
Plain radiograph
- biopsy usually not required
1. Observation
Biopsy
- enlarging
- becomes painful
2. Prophylactic Resection
Doesn't require prophylactic resection because
A. Malignant transformation very rare <1%
- usually in pelvic or shoulder girdle
B. Transform to chondrosarcomas
- low-grade, slowly growing and painful
3. Hand fracture through enchondroma
Allow to heal non operatively if possible
Curettage and bone graft once united
Bone island
Hamartomatous lesion
- island of mature cortical bone found in the midst of normal cancellous bone
>10
M=F
Asymptomatic x-ray finding (usually in adolescents)
Sharply-circumscribed cortical densities
- usually round or oval in shape with smooth, regular borders
- sharp / narrow zone of transition from lesion to cancellous bone
- no evident reaction to the process
Range in size from a few mm to several cm
- more commonly less than 1 cm in diameter
Even cortical texture
Observation
Multiple bone islands
- sclerosing skeletal dysplasia
- AD inheritance
- hips / pelvis / sacrum / femur / humerus
- characteristically periarticular
- lesions asymptomatic and cold on bone scan
- malignant transformation extremely rare
Rare, non-hereditary lesion
- 1: 1 000 000
M = F
Apparent in early childhood and even in the first few days of life
About 50% of persons affected will develop the symptoms by 20 years of age
Unknown
Theory
- lesion arises from an abnormality of the sensory nerve of the affected sclerotome
- sclerotome is a zone of the skeleton supplied by an individual spinal sensory nerve
- represents a basic unit of vertebral embryonic development.
Pain, joint stiffness, and progressive deformity
- mainly the bones of the extremities and pelvis
LLD, deformity
Joint contractures
- secondary to extraosseous bone formation
Can cause spinal stenosis
Can have extensive ST masses, which can ossify
Sclerotic lesions of bones
- undulating cortical hyperostosis
- look like wax dripping down the side of a candle
Increase uptake
Heterogenous
- mix of osseous, fibrous, adipose, cartilage
Variable degree of marrow fibrosis
- with markedly irregular bone with mixed areas of lamellar and woven bone
- mixture of osteocartilagenous, fibrovascular, and adipose tissue is seen in the soft tissue masses
The clinical course is slowly progressive
Severe symptoms may require treatment by sympathectomy or even amputation
Isolated cases of malignancy have been reported in association with melorheostosis
- one osteosarcoma and one malignant fibrous histiocytoma
1. Ollier's
- distributed symmetrically in an extremity
2. Maffucci's syndrome
- randomly distributed throughout the skeleton
- in association with hemangiomas
Site
Enchondromas symmetrically distributed through an extremity
Usually unilateral and monostotic
Epiphyseal, metaphyseal or diaphyseal
Inheritance
Not heritable / embryonal disorder
Problems
1. Often associated deformation of growth
- LLD
- bowing wrist
- bowing elbow
2. Malignant transformation
- 25% at 40 years
Clinical Features
Multiple enchondromas
- randomly distributed
- associated with hemangiomas
Problems
1. 100% risk of malignant transformation
- usually long latent phase
- 30 - 50 years of age
2. Associated with other tumours
- visceral carcinoma
3. Cutaneous hemangiomata
- bring diagnosis to attention
4. Skeletal deformity
- short tubular bones hands & feet
- long bones of UL / LL
- one side of body usually more severe
- palpable mass
- LLD
- bowing of forearms
- varus / valgus of legs
Management
Osteotomy through lesion to correct angulation
Epiphyseodesis or limb lengthening
Curettage & grafting of large lesions interfering with function
Need lifetime vigilance for tumour transformation
Diaphyseal Aclasis / Multiple Osteochondromas
Heritable skeletal dysplasia
AD with variable penetrance (96%)
Incidence of malignant transformation much higher
- 10% overall
- 1 % / year
Chondrosarcoma (CS) > Osteosarcoma (OS)
Secondary CS has better prognosis than primary CS prognosis
Danger areas / central
- pelvis
- scapula
- proximal humerus
- proximal femur
- spine
Mildly short stature
Nerve compressions
Scapular involvement (winging)
Forearm involvement
- ulnar deviation of wrist
- loss of pronation / supination
LLD
Valgus knees
Valgus ankle
CPN compression
1. Coxa Valga
- neck short & broad
2. Genu valgum
3. Ankle valgus
- fibular shortening with valgus distal tibia
- wedge-shaped distal tibial epiphysis
- leads to valgus talar tilt in abnormal mortise
4. Forearm
- ulnar shortening with radial bowing
- ulnar deviation of wrist
- radial head dislocation
Exostoses tend to be more disorganised with bosselated cartilage cap
Excision of symptomatic osteochondromas
Removal of suspicious lesions
Forearm
Most disability
- maybe little functional loss
- pronation / supination decreases with age
No evidence that OT will improve function
- distal radial osteotomy / hemiepiphyseodesis
- lengthening of ulna
- excision of local osteochondromas
Ankle
Chin et al JBJS Am 2000
- demonstrated that early removal in full of osteochondroma
- allowed remodelling of deformity
1. Guided growth
- slow growth medially / screw or 8 plate
- allows lateral fibular growth to correct valgus
2. Supramalleolar osteotomy / Ilizarov correction
- deformity correction
Knee
High incidence of valgus tibial deformity
Case reports of popliteal pseudoaneurysm
It was described in 1983 by Dr. Nora, and is sometimes called Nora's disease or Nora's lesion
Bizarre parosteal osteochondromatous proliferation
Rare lesion
- occurs most commonly in the hands and feet
Adults in their 20's and 30's
Males = Females
Most common in the hands
- followed by the feet
- long bones (commonly of the upper extremity)
- skull, jaw
Hands
- proximal and middle phalanges
- metacarpals
Grows rapidly
- aggressive features on imaging
Mildly painful mass
- seems to increase in size over many weeks or a few months
- usually no history of trauma
Bony mass
- well defined margins
- seen to be applied to the surface of the bone
- it may project into the soft tissues
- lacks the characteristic orientation away from the nearby physis that is seen in osteochondromas.
Wide base
- may appear pedunculated
Matrix
- mature, trabeculated bone
Osteochondromas
- cortex and medullary cavity of the bone is continuous with the cortex and medullary cavity of the lesion
BPOP / Nora's
- cortex and medulla not contigous with cortex
- no cartilage cap
Typical tumour picture
- high SI on T2
- low SI on T1
No cartilage cap
Parosteal / periosteal OS
Gross
- nodular surface covered with glistening cartilage.
- bone in the lesion has a distinct blue tint
- The cut surface of the lesion bleeds freely
Very cellular cartilage
- proliferation of bizarre fibroblasts
- disorganized bone with spindle shaped fibroblasts in the intertrabecular spaces
Confusion with
- chondrosarcoma
- fibrosarcoma
- low grade parosteal osteosarcoma
- conventional osteosarcoma.
Lesion is benign
Wide excision
- limits local recurrence
Recurrence
- may recur locally in as many as 50% of cases
- seen from 2 months to 2 years after surgery
Uncommon
< 1% Primary bone tumour
Young boys
- second decade
Similar to OO
Spine 30%
- especially posterior elements
Long bones 35%
Back or limb pain
- pain less severe than OO
- not dramatically relieved by aspirin
Limp
Scoliosis
Spine
- difficult to see
- irregular cortex
- sclerotic or loss of pedicle
- enlargement of spinous process
Long Bone
- less diaphyseal occurrence than OO
- more common meta-diaphyseal
- large faintly radiolucent lesion
- thin reactive rim
- may be expansile
Demonstrates spinal lesion well
- bone expansion
- intralesional stippled ossification
Uptake +++
Osteoid osteoma
- < 2 cm
> 2cm diameter
- less reactive rim
- otherwise identical to OO
- osteoid
Can be difficult to differentiate from OS
- may also see changes of ABC
On rare occasion have acted aggressively
- bone destruction & soft tissue extension
- however don't metastasise
1. Excision with wide margin
- preferred
2. Extended curettage
- indicated in spine
- recurrence not uncommon, & difficult to treat
3. Radiofrequency ablation
Outgrowth of benign cartilage from bone
50% of benign bone tumours
- single lesion in 90%
1. Multiple
Tumour suppressor gene
- family of tumour suppressor genes involved
- have been identified in chondrosarcomas
- 2 hit model of tumourigenesis
Both alleles must be mutated for an osteochondroma to form
- if inherit an abnormal allele need other allele to undergo mutation to form osteochondroma
2. Single
? Secondary to injury of growth plate
- defect in Perichondral Ring La Croix
- results from herniation & separation of fragment of physis through the periosteal bone cuff
Grows by endochondral ossification of enlarging cartilage cap
- stops at maturity
Low-grade Chondrosarcoma
- isolated lesion < 1%
- more common with central lesions
Suspicious features (6)
1. Growth after maturity
2. Hot bone scan (can be from overlying bursa)
3. Increased thickness of cartilage cap on CT
- > 1-3 cm (Enneking)
4. Pain
5. Pathological fracture
6. Disappearance of calcification
Enneking
- when the rim of cartilage in an adult exceeds 25 millimeters, it is highly suggestive of malignant transformation
Any bone formed by endochondral ossification
Arises from cortex of long bone adjacent to physis
Most common
- around knee
- proximal humerus
Commonly noticed during adolescent growth spurt
Symptoms of mass lesion
- pain & tenderness
- decreaed ROM
- compression of NV structure
Protuberant bony lesion
- arising adjacent to physis
- directed away from joint
- cortical bone continuous
- marrow space continuous
- cartilage cap may be calcified
Types
1. Pedunculated / exostosis
2. Sessile
Cortex and medullary cavity of normal bone contiguous with osteochondroma
See cartilage cap
- iso-intense with hyaline cartilage
Gross
- looks like cauliflower
- surface covered with irregular cartilage
- cartilage usually 3-5 mm adults
- 5 - 10 mm children
- bone has cortex & medulla
Histology
- cap resembles disorganised physis
- irregular shaped underlying trabecular bone
- may contain calcified cartilage matrix
DDx
Juxtacortical OS / CS
Periosteal Chondroma
Osteoma
1. Excise painful mass
2. Tendon / NV impingement
3. Restore joint motion
4. Correct deformity
5. Biopsy suspicious lesions
6. Central / pelvis / scapula
- due to higher malignant transformation rate
Benign, bone-forming neoplasm
- characterized by a small nidus of neoplastic tissue
- surrounded by a wide zone of mature, reactive bone
10% of benign bone tumours
Age 5-25
M:F 2:1
Unknown
- thought may be glomus tumour of bone
Pain secondary to prostaglandin production
Intra-cortical position usually
60% femur, tibia
- usually at end of diaphysis
- cancellous or cortical
Posterior elements spine
Characteristic pain
- intense, unrelenting ~ toothache
- night pain
Relief by aspirin / salicylates
- dramatic
- often within 30 minutes of one dose
May be worsened by ETOH
Scoliosis
Joint effusion if juxta-articular
Gradual resolution with time
A. Medullary OO
Four Diagnostic Features / 50% show all 4
1. Sharply round or ovoid
2. < 1cm
3. Homogenously dense centre
4. ~ 1mm peripheral radiolucent zone
B. Intra-cortical OO
- area of dense bone
- often fusiform-shaped
- central nidus usually not seen
- mimics stress fracture
Uptake +++
Useful to locate lesion especially in spine
Thin slice CT best investigation
- lucent nidus
- surrounding dense bone
Gross
Lesion is nidus
- < 1 cm diameter
- cherry red & granular
- dense reactive bone peripherally
Histology
Immature trabeculae enveloped by prominent osteoblasts / clasts
Lucent zone
- surrounding zone of hyperaemic fibrous tissue
- thin lacelike woven bone seams
- AKA osteoid seams
- haphazard
- numerous vascular channels & rich nerve fibres
- osteoblasts & giant cells surround
- no chondroid elements
No haemopoietic elements in vascular channels
Osteoid surround by vascular fibrous stroma
Cortical
- infection
- stress stress fracture
- parosteal OS
- osteoblastoma
Medullary
- VINDICATE pneumonic
Can resolve
- ? spontaneously heals
- takes a long time
- NSAID for pain relief
- doesn't progress to cancer
Goal is to remove the nidus
Gold standard
- ensures all of lesion excised
- weakens bone
- risk of fracture especially with lesion in femur
- need bone graft & protection
- send for intra-operative fresh frozen section to ensure have excised OO
Technique
- intraoperative CT guidance
- direct incision over lesion
- shave cortex off with high speed burr to reactive bone
- scoop nidus out once hit hypervascular zone & sent for FFS
- burr 2mm zone out
- can leave strong reactive bone behind
CT guided in xray suite
- doesn't produce tissue for histology
Technique
- GA
- introduce electrode under CT
- can take tissue for histology
- radiofrequency
- increase temperature for 6 mins to 90o
Contraindication
- spine
- risk thermal injury to spinal cord / nerve roots
Results
Rosenthal et al JBJS Am 1998
- equal rates recurrence (9%)
- no complications
- increased patient satisfaction
- drastically reduced in patient stay
Benign, hamartomatous bone-forming lesion arising from the surface of the affected bone
Excrescence of dense bone which arises from the surface of bones formed by intra-membranous ossification
Age 25-50
M=F
Skull or mandible
- classically
Shafts of long bones
- often see posterior femur
- similar location to parosteal OS
"flat bones and tibial diaphysis"
Gross
- dome-like outcropping
- dense bone
- covered by a capsule confluent with the periosteum
Histology
- heavy trabecular bone
- matures into dense cortical bone
- over-maturation
- many small haversian canals
- some canals are obliterated
Parosteal osteosarcoma
Exostosis
Active stage 2 lesion
- never goes to 3 or 1
Gardner's Syndrome
Intracapsular or marginal excision
- removing the lesion from the surface of the bone
- negligible risk of recurrence
- wide en bloc excision not necessary
Malignant cartilage producing tumour
20% of primary bone tumours
3rd most common
- 1 in 500 000
Relatively non-aggressive / usually Grade I
Average age 40
Male > Females
Arises de novo
Chondrosarcoma variant
- arises in existing cartilage lesion
- age > 40
- most common in osteochondromas / enchondromas
- also FD / UBC / Paget's / Radiation
A. Secondary chondrosarcoma in Osteochondroma
< 1% chance per lesion
Malignant features
- growth after skeletal maturity
- pain
- calcification in cartilage cap
- disappearance of previous calcification
- cartilage cap > 1-3 cm
- hot on bone scan
- erasure of smooth outline
B. Secondary chondrosarcoma in Enchondroma
Malignant features
- scalloping (endosteal erosion)
- periosteal reaction
- fluffy calcification
- size > 6-10 cm rarely benign
- malignant rare < 20 years
- solitary < Ollier's / Maffucci's
C. Grade 1/2
Intra-osseous cartilage forming tumour with worrisome clinical or radiological changes
- i.e. pain at site of previous painless enchondroma
- expansion / large size / endosteal scalloping
Problem
- is a diagnostic and management dilemma for radiologists / pathologists / orthopaedic surgeons
Management
- biopsy
- can miss malignant areas / sampling errors
- probably best to excise in entirety via curettage to examine all tissue
- covert to resection if frankly malignant
1. Dedifferentiated
Area of low grade with juxtaposed area of anaplastic sarcomatous component
- very aggressive tumour
- prognosis is poor
- few survivors two years after diagnosis
2. Clear Cell
Epiphyseal lesion in young males
- end of major long bones
- proximal humerus and distal femur
Likely malignant chondroblastoma
- destructive low grade
- slow growing
- metastasis very rare
Histology
- many cells with abundant clear vacuoles lying between abundant heavily calcified chondroid material
- DDx renal cell ca / clear cell sarcoma / adenoca
Treatment
- wide excision
The benign appearance and lack of calcification is often misleading
3. Mesenchymal
Rare
- young patient
- often extra-skeletal, ribs and jaw
- ill defined osteolytic lesion
- high metastatic potential
10 year survival 30%
Characteristic biphasic pattern
- areas of cartilage or chondroid matrix
- interspersed with areas of small spindle cells similar to Ewing's in a hemangiopericytoma pattern
Treatment
- surgery + chemotherapy
1. Central
Within diaphysis of long bone
Lytic lesion with punctate or spotty calcification
- can look like bone island
- 3/4 calcification present on plain film
Endosteal scalloping is hallmark of chondrosarcoma
- periosteal reaction often minimal
- soft tissue expansion
- in metaphysis may only see subtle periosteal reaction
- expansion with cortical thickening characteristic (20%)
2. Peripheral / Juxtacortical
Rare
Faintly visible sparse calcification in soft tissues
- often behind knee
- radiating spicules at right angles to cortex
- > 2.5cm (OS <1.5cm)
Usually no medullary involvement
- cortex rarely affected
- Codman's triangle occasionally
3. Soft Tissue
Rare
Treat as soft tissue sarcoma
Pain (80%)
- pain in benign cartilage tumour must be assumed to be malignant
Mass
Referred pain
Pathological fracture
Incidental finding
Pelvis most common
Shoulder / Femur
Worrisome features
- central
- large > 5cm
- cortical / endosteal scalloping
- cortical break through
- soft tissue mass
- periosteal reaction
Gross
Pearly white
- cauliflower-like mass
- surrounded by pseudocapsule
Histology
Lobules of cartilage
Matrix may have
- calcium / necrosis / myxoid degeneration
Features that suggest malignancy
- pleomorphism
- hypercellularity
- mitotic figures
- double nuclei in single lacunae
- multinucleated giant cells
Can be a great diagnostic challenge for MSK pathologist
- DDx between benign active and low grade (grade 1/2)
- especially difficult between enchondroma and low grade central CS
Borderline / Grade 1/2
Low-Grade / Grade 1
Mild cell atypia and mild hypercellularity
- frequent calcificaiton
- mitoses absent / necrosis rare
- occasional bi / trinucleate cell
Medium-Grade / Grade 2
More cellular
- 1-2 mitoses / high power field
- less calcification
High-Grade / Grade 3
Marked atypia & mitotic figures
- densely cellular
- many double nuclei
- no calcification
- obviously anaplastic
- must have chondroid
Treatment is wide resection
Highly resistant to chemotherapy & radiotherapy
- rate of DNA synthesis slow
Radiotherapy
- only used if inoperable
- high grade lesions with incomplete margins
Exceptions
- mesenchymal -> chemo & radiotherapy
- dedifferentiated -> chemotherapy
1. Grade
Low / moderate Grade - 90% 5 year survival
High Grade - <10% 5 year survival
2. Site
Peripheral - 80% 10 year survival
Central - 30% 10 year survival
Incidence 15%
- 40% preceded by local recurrence
- local recurrence 6x risk for metastasis
Grade II: 15 - 40% risk metastasis
Grade III: 75% risk metastasis
Treatment algorithm similar to OS
Overall prognosis similar to OS
- 70% long term survival
A malignant neoplasm composed of small round cells of uncertain histogenesis
Recent data suggests it is of neuroepithelial derivation
- ? neuroectodermal cells
- mesenchymal stem cell of neural crest origin
Translocation
- T (11, 22)
- balanced
Ewing's tumour & PNET have a similar histogenesis
Central
- pelvis (12%)
- scapula
- vertebrae
- rib
- sacrum
Peripheral
- femur (20%)
- humerus (11%)
- fibula
Usually 2nd decade
- 5-30 years
- peak 10 years
M:F 3:2
Usually complain of pain & then swelling
± Systemic symptoms
- fever, weight loss, malaise
- poor prognosis
Usually large soft tissue mass
May have local signs
- tenderness
- erythema & induration
Diffuse permeative destruction
Extension into soft tissue
Periosteal reaction
- codman's triangle
- onion skinning
- sunburst appearance
Ewing's
Osteomyelitis
EG
Elevated ESR & LDH
- poor prognosis
May have anaemia or leucocytosis
Pulmonary metastasis (20% GIII)
Shows intramedullary extent
- extraosseous extent more difficult
- reactive oedema difficult to distinguish from tumour
Shows occult bone metastases
- 10% have multiple bone involvement at time of presentation
Important part of staging for Ewing's
Usually Grade IIB lesion
- high grade & extracompartmental
20% Grade III
- pulmonary mets
In reality all have micrometastasis
Bone marrow aspirate and trephine
- at distant site
- look for marrow spread
Sheets of uniform round cells / small round cell tumours
- cells have distinct nuclei with minimal cytoplasm
- indistinct cytoplasmic border
- mitotic activity seldom high
Areas of necrosis
- 'geographic necrosis'
- pseudorosettes of cells around central necrosis
Use histology, immunohistochemistry, EM and cytogenetics
- Ewings
- PNET
- lymphoma
- rhabdomyosarcoma
- metastatic neuroblastoma
1. Ewings
PAS reaction positive 90%
- stains glycogen and mucin
- other tumours can be positive i.e. neuroblastoma
Ewing / PNET
- positive to vimentin / S100 / MIC 2
- MIC 2 specific for neuroectodermal tumours
Cytogenetics
- 11:22 translocation in all PNET
2. PNET (Primitive Neuroectodermal Tumour)
Variant of Ewing's
Composed of
- adult neuroblastoma
- Ewing-like tumour
- Askin tumour - thoracopulmonary PNET
Separate group because older age group with worse prognosis
3. Lymphoma of bone
Most important
- older age
- more bone formation
- "common leukocyte antigen" positive
4. Rhabdomyosarcoma
Actin / desmin / myoglobin positive
EM
- cytoplasmic filaments
- occasional Z bodies
- prominent IC glycogen storage deposits
5. Metastatic neuroblastoma
- PAS positive
- negative to vimentin, MIC 2
Other
- small cell OS
- mesenchymal cell chondrosarcoma
- osteomyelitis
- Eosinophilic Granuloma
Irradiation only
- poor results
- survival 25% at 5 years
- local recurrence 35%
- high complication rate (soft tissue damage / pathological fracture / premature closure of physes / 2° sarcoma)
Chemotherapy is mainstay & primary treatment
- surgery / radiotherapy adjuvant treatment
- significantly more successful
- 60% survival at 5 years
- 40% if metastasis on diagnosis
1. Neoadjuvent chemotherapy
2. Restage
3. Surgical resection
- if can get adequate margins
4. Chemotherapy
5. Radiotherapy
- if margins inadequate
Usually dramatically shrinks tumour
- entire soft tissue component can resolve
- period controversial
- principle is to treat to maximum response
Pre - chemothearpy
- LFT's / Renal function / Cardiac echo or Thallium scan prior to intensive chemotherapy
- preserve sperm / ovum
VAAC Regime
- Vincristine
- Actinomycin
- Adriamycin
- Cisplatin
Alternate with
- Iphosphamide
- VP 16 = Etoposide
See response following neoadjuvent chemotherapy
- MRI of affected region
- CT Chest
Excision best if possible
- amputate if limb salvage not possible
- irradiation if resection not feasible
- resect bone to pre-chemo margin
- resect ST to post-chemo margin
Assess histological response
- > 95% necrosis
Surgery improves survival
- removes remaining cancer cells
- removes chemo resistant cells
Continue neoadjuvant regimen
- total chemotherapy is usually 18/12
1. Site
- hands and feet better than pelvis and central
2. Size
- > 8-10 cm do worse
- > 100 ml on CT
3. Metastasis at diagnosis
4. Response to chemotherapy
- > 95% necrosis
5. Surgery
- improves survival if resectable
No metastasis at diagnosis
- 60% 5 year
Metastasis at diagnosis
- 40% 5 year
Local recurrence
- 5% local recurrence with surgery
- 25% without
Indications
- incomplete surgical margins
- unresectable
If need to use RTX, should use prosthesis rather than allograft
Complications
- physeal arrest
- joint contractures
- muscle atrophy
- pathological fracture
Secondary malignancy / sarcoma
- increased with young age
- 40x increase if >60 Gy
- strong cumulative risk at 10 years of 35% secondary malignancy
Uncommon
- 4% OS
Females more common
- similar to GCT
Less aggressive locally
- less metastasis
- size / location & duration of symptoms don't correlate with outcome
Arise from cortex of bone / periosteum
- parosteal
- periosteal
- high grade juxtacortical
Comprise most of the 4%
Older (20-40)
Females
Lower grade
May dedifferentiate (late) into high grade lesion
Arises from periosteal surface
- in the soft tissues adjacent to the periosteum
Most common in posteromedial distal femur
- popliteal Fossa
Also tibia & humerus
Slow indolent growth with eventual invasion of the underlying bone
Painless block to knee flexion
May look like osteochondroma
- large lobulated broad-based lesion
- mature bone arising from cortex
- underlying cortex may be thickened
- 25% invade periosteum
- lesion dense with bony pattern
"String Sign"
- wraps around bone with intervening periosteum
- gives well-defined radiolucent line
- thin radiolucent line between lesion & cortex
1. Parosteal OS
- attached to cortex growing into ST
- normal cortex intact
2. Osteochondroma
- cortex of bone becomes cortex of osteochondroma
- there is modelling of cortex into the tumour
- medullary canal confluent with Exostosis
- posterior femur rare
NB Cortical tumours of posterior femur should be considered malignant
Osteochondroma
Myositis Ossificans
- more mature in periphery
- "like an agg"
- not attached to bone
Classic OS
Periosteal Chondroma
Osteoma
Subperiosteal Haematoma
Low grade
Regularly arranged bone
- background of spindle cells & fibrous tissue
- may have cartilage cap
- can encircle bone
Wide Resection
Margins
- 7cm proximal & 5cm distally
- femur: resect posterior capsule & condyles with lesion
Prognosis
80% cure with surgery alone
Rare +++
15-25
Diaphysis of major long bones
- typically anterior proximal tibia
- humerus
"Peri is a rare bad boy"
- higher grade
AKA High grade juxtacortical chondroblastic OS
- classically shows cartilage +++
- c.f. parosteal OS
Punched out lesion
- calcified mass
- in a saucer shaped defect in the cortex
Wide resection with neoadjuvant & adjuvant chemotherapy
- DXRT stop local recurrence
Uncontrolled proliferation of single clone of plasma cells
Most common malignant tumour of bone
Age 50-60
2-3 / 100 000
Highly differentiated B lymphocytes
- associated with abnormality of protein synthesis
Usually bone marrow of entire skeleton involved
1. Multiple Myeloma 95%
2. Plasmacytoma 5%
- solitary bone or soft tissue lesion
- usually axial skeleton
- usually disseminates to MM in 5 - 10 years
Always spine
Common in skull, ribs, sternum and pelvis
Bone pain / fatigue / fever / night sweats
Normocytic normochromic anaemia
Other signs bone marrow depression
- i.e. coagulation defects
- leukopenia
- thrombocytopenia
Elevated ESR > 100
Bence Jones Proteins in urine 50%
Serum & Urine Electrophoresis
- monoclonal antibody band
- most sensitive
Hypercalcaemia
Chronic Renal Failure
Elevated Serum Urate / Gout
Anaemia
Coagulation defects
Infection 2° immunological deficit
Hypercalcaemia
Amyloidosis 10%
CRF
Gout
1. Radiographic hallmark is punched out lytic lesions
- axial and appendical skeleton
- widely disseminated / soap bubble appearance
- no sclerotic reaction
2. Diffuse osteopenia
- in 15% to 25% of patients, no discrete lysis occurs
- diffuse osteopenia and osteoporosis are the only skeletal manifestations
3. Vertebrae Plana
4. Pathological Fracture
5. Pepper pot skull
25% negative
- no malignant or reactive bone formation
Required if negative bone scan
Xray
- skull / spine / humerus / femurs / pelvis / chest & ribs
Definitive Diagnosis
Sheets of plasma cells
- clock-faced eccentric nuclei
- perinuclear clear area
- increased rER on EM
- no background stroma
Cellular atypia not prognostic
May see amyloid
Diagnostic criteria
Single osseous lesion confirmed on histology
Bone marrow aspirate from separate site
- < 10% plasmocytosis
No significant BJ in urine
No Ig abnormality in serum or urine
Clinical
Tend to be younger and have better prognosis
- usually long bone or vertebrae
- in spine commonly present with rapidly progressive paraplegia
- this is more common in plasmacytoma then multiple myeloma
NHx
70% of plasmacytoma will progress to multiple myeloma
Management
- requires biopsy
- resection of lesion if possible
- aggressive DXRT otherwise
Prognosis
30% cured by surgical en bloc excision and radiotherapy
Management
Chemotherapy
- corticosteroid
- alkylating agent - Melphalan / Cyclophosphamide
Radiotherapy
Surgical stabilisation of pathological fracture
Orthopedic Management
1. To confirm diagnosis - biopsy isolated lesion
2. To treat impending or actual pathological fracture
3. Rarely to excise solitary lesions
Prognosis
Multiple myeloma very aggressive with early death
Highly malignant spindle cell sarcoma of bone in which the malignant cells produce osteoid
- aggressive
- most High grade (II)
- most extracompartmental (IIB)
Exception is Juxtacortical (IA)
Most common malignant primary bone tumour excluding myeloma
Bimodal peak
1. Second decade / teenagers
- 75%
2. Elderly / 7th decade
- Paget's
In fact very rare to see under 13 years
- if looks like OS in this age group then probably Ewing's
M > F 3:2
Li-Fraumeni syndrome
Retinoblastoma - FHx / p53 Defect
Radiotherapy
Paget's disease
Anatomical
Classic Central
- classic high grade
- rare low grade
Juxtacortical
- parosteal
- periosteal
Extraskeletal
- Jaw
Pathological / Lichenstein's
- see below
Aetiological
Secondary
- Paget's
- previous radiotherapy
- OM
- Fibrous Dysplasia
- Chondrosarcomatous dedifferentiation
Metaphysis of long bones
- distal femur 35%
- proximal tibia 20%
- proximal humerus 10%
Can cross into epiphysis / occasionally in diaphysis
Pain
- often activity related
- likely due to microfracture
- most patients relate onset of pain to some minor trauma
- sometimes at night
No systemic symptoms
Mean symptom duration is 4/12
- 10% metastasis on presentation
- 1% pathological fracture
Usually diagnostic
1. Metaphyseal - involves medullary canal
2. Permeative cortical destruction
3. New bone formation / osteoid
4. Wide / permeative zone of transition / non geographic
5. Codman's Triangle
- triangular periosteal new bone formation
- at proximal and distal cortical margins
- non specific
- reaction to rapid growth
6. Soft tissue component
1. Determines the marrow extent of tumour
- helpful in determining appropriate resection level
- satellite lesions
- metastasis within reactive zone
2. Identify skip lesions
- metastasis outside reactive zone
- sagittal and coronal images of the entire bone
3. Soft tissue component
4. Relationship to NV structures
5. Articular involvement
- usually runs along ACL / PCL
Complementary to MRI / very useful in the pelvis
1. Resect with 3-4cm margin from bone scan uptake
- resect skip lesions
2. Identifies metastatic disease
10% present with pulmonary metastasis
- lungs most common site
- detect > 3 mm
- if resectable then resect lung metastasis via sternotomy
ALP & LDH
- can be increased
- worse prognosis
ESR
- May be mild increase
Gross Pathology
Starts with intramedullary focus
- bony with areas of focus & haemorrhage
- skip lesions common 5-20%
- grows up & down medulla
Histology
Must see malignant spindle cell stroma producing osteoid
- can be difficult to find osteoid
- therefore adequate sampling is essential
Pleomorphic spindle cells
- hyperchromatic nuclei
- atypical mitotic figures
Can mistake fracture callous or periosteal new bone for that produced by malignant cells
Low grade central / parosteal OS
- much less cellular
1. Osteoblastic (50%)
- prominent osteoid
- delicate network of eosinophilic matrix with both benign and malignant osteoblasts throughout
2. Chondroblastic
- prominent cartilage
- still have malignant osteoid
3. Fibroblastic
- prominent fibrous tissue
- look like fibrosarcoma
4. Telangiectatic
- worst prognosis
- cystic pools of RBC / Giant cells
- may look completely lytic & expansile on Xray
- often with benign giant cells
- can mistake for ABC or GCT
- however see cellular atypia etc amongst stroma
5. Giant Cell Rich Osteosarcoma
- older patients
- similar to MFH
- difficult diagnosis
6. Small Cell Osteosarcoma
- similar appearance to Ewings
- responds to chemotherapy like PNET
- nests small cells
Historically
- amputation
- 1970's 5 year survival 20%
Now
- 70% overall survival
- 90% limb sparing surgery
1. Accurate clinical staging
- local (cross sectional imaging - CT / MRI)
- systemic (bone scan & CT chest / abdomen
- biopsy
2. Neoadjuvant chemotherapy
3. Restage
- locally and systemic (MRI / CT Chest)
4. Wide resection
5. Post operative chemotherapy +/- radiotherapy if positive margins
Concept
Systemic treatment
- treats micrometastasis
- allows limb salvage
Rosen in vivo response dictates outcome
Outcome best predicted by response as per Rosen
- some OS have P-Glycoproteins pump
- remove chemo from the cell
Grade 1 = no cell death
Grade 2 = Partial <90%
Grade 3 = Necrosis >90%
Grade 4 = Complete necrosis
Grade 1 & 2
- < 50% survival
Grade 3 & 4
- > 75% long term survival in OS and MFH
Regimen
Neoadjuvant & Adjuvant
2 cycles pre-operative MACI
- MTX
- Adriamycin (Doxorubicin)
- Cisplatin
- Ifosphamide
Timing
- usually 3/12 after diagnosis
- usually 2/52 after end neoadjuvant chemotherapy
- post chemotherapy tumour is smaller & tends to have a "rind" that makes resection much easier
Goal
- resection with wide margin
- 7cm proximally, 5cm distally
Options
Amputatation
Limb Salvage Surgery
80% patients can have limb salvage
Contraindications / PIN LEG
1. Pathological fracture
2. Infection
3. N/V involvement
4. Immature skeletal age if LLD >6-8cm
5. Extensive muscle involvement
6. Poor biopsy (instead of Good)
Technique
1. Resection of tumour & biopsy tract
- major N/V bundle must be free of tumour
- wide resection of affected bone
- normal muscle cuff in all planes
- biopsy tract removed en bloc
- 5cm margin on MRI
- adjacent joint and capsule should be resected
- extra-articular resection preferred
- articular resection mandatory if effusion present
- use tourniquet --> if site contaminated at histology allows amputation to be performed above tourniquet level
- motor reconstruction by local transfer
2. Skeletal reconstruction
- usually 15-20 cm defect
- endoprothesis / arthrodesis / allograft
3. Local soft tissue and muscle transfers
- adequate soft tissue cover mandatory
Incidence 12%
- poor outcome
- DXRT to prevent local recurrence if +ve margin
Can still treat with an attempt at cure
- resectable disease =< 15 pulmonary metastasis + extremity tumour
- treatment is along similar lines
- neoadjuvent chemo
- tumour resection / amputation + median sternotomy and resection of mets
- aim is to relieve tumour burden
- if unresectable then chemotherapy is more appropriate
Single most predictive factor is the presence or absence of detectable metastasis at presentation
Survival
IIB 60% 5 year
III 50% 5 year
Significant improvement recently
- improved surgical resection
- early resection of lung metastasis
- improved adjuvant chemotherapy
Metastasis - 10 - 20% 5 year
Resectable pulmonary metastasis post treatment
- 20 - 40% 5 year
Local recurrence
- 5 - 10 % 5 year
Basic Principles
If survive 2 years probably will survive
- no difference in survival between amputation & limb salvage
- long-term survivors 7% risk of developing second tumour due to treatment
Poor Prognostic Signs
Age < 10 years
Proximal humerus / central lesion
Poor response to chemotherapy
Tumour size > 15cm
Symptoms < 6/12 = aggressive
Pathological fracture
NV involvement
Pelvis much worse than femur which is worse than tibia
Telangiectatic worst
Secondary OS
The identification of skeletal metastasis & fixation prior to fracture
50% of new cancer cases have metastasis
- 1% have pathological fracture
- increasing with more aggressive palliative care
Life expectancy after diagnosis
- 40% at 6/12
Non-operative treatment poor
- morbidity
- non-union
Improves survival
- 20%
More difficult to manage once fractured
1. Metastasis with unknown primary / rare
2. Pathological fracture
3. Metastasis with known primary / commonest
1. Life expectancy > 2/12
2. Tolerate major OT
3. Stable fixation possible
Bone seeking malignancies
- 80% PBL
- prostate, breast, lung
- occult metastasis usually breast & prostate
Also Kidney, Thyroid & GIT
- 20%
- remember the hexagon
- with malignant melanoma & lymphoma in centre
80% axial
- earliest
20% appendicular
- usually proximal especially proximal femur +++
1. Haematogenous
Cells carried on fibrin raft
- multiple steps
- cross many tissue layers
- tissue preference
2. Lymphatic
- renal cell
- OS
3. Direct
- rare
4. Iatrogenic
Lytic / Sclerotic / Mixed
Purely lytic
- lung
- kidney
- breast
- thyroid
- GI
- neuroblastoma
Mixed
- breast
- prostate
- lung
- bladder
Blastic
- prostate
- breast
- bladder
- GI
- lung (oat cell)
1. Osteoclast mediated
- 2° local factors eg TNF
2. Direct destruction
- via enzymes
75% of metastasis
Cause
1. Stimulated nerve ends by direct invasion of tissue
2. Periosteal stretching
3. Fractures
4. Nerve irritation
Need > 50% bone loss to see
Remember to xray entire bone
- especially NOF fracture
- need to bypass all lesions
Most sensitive screen
False negative ~10%
- Myeloma / EG / Melanoma / RCC
- overwhelm osteoblasts via Osteoblast Inhibiting Factor
Clin Orthop 1989
- 38 patients treated with DXRT without surgery
- most breast cancer
- developed scoring system
- predicts post DXRT fracture risk in preDXRT long bones
- risk of fracture within 6 months
- irradiated without fixation
Four risk factors
1 2 3
Site: Upper Lower Peritroch
Pain: Mild Mod Functional
Lesion: Blastic Mixed Lytic
Size: <1/3 1/3-2/3 >2/3
Score < 7 irradiate safely
- < 4% chance fracture
Example
- large lytic lesion in proximal femur
- will score 9 immediately
Scores
8 - 15% chance # post DXRT
9 - 33%
10 - 82%
11 - 96%
12 - 100%
After pathological fracture
- lung Ca = 100% mortality 6/12
- breast Ca = 50% mortality 6/12
Median survival metastatic disease
- 50% survive 6/12
- 30% survive 1 year
- lung 6/12
- breast 18/12
- prostate 24/12
Worse if
- hypercalcemia
- lung mets
- paraplegia
1. Appropriate patient selection
Need to live longer than time for recovery from the operation (> 2/12)
Poor prognosis
- lung
- visceral & bone metastasis
- short interval between diagnosis & metastasis
2. Reconstruct so that FWB immediately
Overall union rate is 35%
- <15% for lung & myeloma
3. Address all involved areas in the bone
4. DXRT post-op
- entire femur should be irradiated after reaming
- patients that have DXRT have improved function & lower re-operation rate
Prediction of prognosis
- score correlates to prognosis
- six parameters with a total score of 0 to 12
Parameters
General condition according to Karnofsky's performance status
2 points for 80-100%
1 point for 50-70%
0 points for 10-40%
No of °spinal bone mets on scan
2 points for none
1 point for 1-2
0 points for 3+
No of vertebral metastasis
2 points for 1
1 point for 2
0 points for 3+
Metastasis to the major internal organs including lungs, liver, kidney and brain
2 points for no met
1 point for operable lesion
0 points for inoperable lesion
Primary site
2 points for thyroid, breast, prostate & rectum
1 point for kidney & liver, uterus, bladder, gallbladder or unidentified
0 points for lung & stomach
Spinal Cord Palsy
2 points for Frankel E
1 point for Frankel C or D
0 points for Frankel A or B
Prediction
Average period of survival
Score of 9 to 12 > 12 /12
Score of 6 to 8 - 3 12/ 12
Score of 0 to 5 < 3/12
Remember principles are same as normal fracture fixation
- fixation will eventually fail if fracture does not unite
Healing is slower than normal bone
- irradiation reduces this even more
- 50Gy >14 days after surgery doesn't produce notable increase of non-union
Goal is to obtain union
- avoid fracture during procedure
- preserve soft tissue envelope
- rigid internal fixation
- if large lesion >75% of cortex augment with PMMA
Pre-op embolize vascular tumours
- renal cell
Nutrition
- consider hyperalimentation
Hypercalcaemia
- from tumour / fracture / metastasis
- stones, bones, abdo moans (pancreatitis), psychic moans
- treat with bisphosphonates -> inhibit osteoclastic activity
High uric acid levels
- prophylaxis against gout
Marrow suppression
- from chemotherapy or mets
- risk infection and excessive blood loss at time of surgery
DVT prophylaxis
Post-op DXRT for local control
- start Day 14
- 30 Gy / 3000 Rads in fractionated doses
There is a period of transient osteoporosis after DXRT in first 2 weeks
- increased fracture risk by 25-40%
- also increased infection rate
Harrington 1986
65-85% metastasis will heal with radiotherapy if no fracture
- almost normal bone structure takes 4-6/12
Healing of pathological fracture without fixation very poor
- non-union 65-80%
With prophylactic fixation & 2200 rads
- 96% remission rate (of which 26% is permanent)
- 94 % bone healing
- 86% union of pathological fracture with interlocking fixation
Harrington 1986
- aim to span diseased segment with biomechanically strongest construct
- intramedullary best
- prosthetic replacement has better results than ORIF
- bone grafts not effective with post-op DXRT
PMMA
Excellent
- improved results in both animal & human studies
- increased construct strength / bending strength
- improves hardware fixation to bone / improves screw hold
- better pain relief
- immediate weight bearing
- not effected by DXRT
Thyroid Breast
Lung MM Lymphoma Kidney
Bowel Prostate
Most common site for "unknown primary"
- lung 63%
- kidney 10%
Most common "known primary"
- breast and prostate
1. Medical History
- previous malignancy
- symptoms for most likely primaries (above)
- history smoking, coughing up blood
- breast lumps
- blood in urine
- bowel disturbance / blood
- fevers / temps / generally unwell
2. Physical exam
- breast in women
- prostate in men
- lymph nodes
- thyroid in neck
- skin
3. Plain X-ray
- bone involved
- any other bones with pain
- CXR
4. Routine bloods
- FBC ELFT
- ESR / CRP
- TFT
- PSA
- Se electrophoresis / BJ urine
- Ca, PO4, Alk Phos
- LDH
- blood film / suspect leukaemia
5. Bone scan
- polyostotic / monostotic
6. CT Chest/ Abdo / Pelvis
- lung / bowel / renal
7. Biopsy of most accessible lesion
Multiple lesion
- biopsy most accessible
If isolated bony lesion
- need to treat as primary bone tumour
- stage locally / MRI
- consult with local orthopaedic oncology unit
- discuss biopsy procedure
Bone marrow biopsy
- lymphoma / myeloma
Simon et al JBJS Am 1993
- 40 patients prospective study
- allows identification of 85%
- lab values non-specific in all cases (myeloma excluded)
- history and examination found primary in 8%
- CXR found 43% of primary
- most important finding was benefit of CT
- 75% of primary diagnosed on CT chest, abdo & pelvis
- biopsy diagnosed 8% and confirmed in 30%
Fractures
Principle
- do very poorly with fixation
- hemiarthroplasty or THR
- stem should be 2.5 cortical diameters beyond any area of weakness
- THR if acetabulum involved
Lane JBJS 1980
- 167 patients post proximal replacement
- median life expect 5.6m
- none had mechanical complications
- all walked
Prosthesis
THR
Proximal femoral prosthesis
- indicated for extensive metastasis
- expensive / high dislocation rate due to loss of abductor mechanism
- hemiarthroplasty better to avoid dislocation
Lesion only
Options
- either pin & plate / reconstruction nail
- depends if further lesions in femur
- augment with PMMA
Fracture / Very Large Lesion
- calcar replacement prosthesis
Management
Reconstruction nail preferred
- place distal vent prior to reaming
Harrington classification
Type I
- minor cavitary defect
- medial and superior walls intact
- standard cemented cup
Type II
- major deficit in medial wall
- rim intact
- wire mesh to contain cement or protrusio ring
Type III
- massive deficit in lateral wall & superior cortex
A. Flexible threaded Steinmann pins & protrusio cup
- anterior column inserted antigrade through iliac crest
- posterior column inserted retrograde thru acetabulum while palpating sciatic notch & SIJ thru iliac crest incision
B. Saddle prosthesis
Management
IM Nail
Options
- Screw plate / Blade plate
- retrograde nail
- modular knee prosthesis
Options
- ORIF
- tumour prosthesis
RCC
Operative v Non operative
Surgical Options
- locked IM nail
- PMMA + plate (probably more secure with less pain)
Weiss et al JBJS Br 2011
- 63 patients
- 11% reoperation rate
- good return of early function without pain
Dijkstra Eur J Surg Oncol 1996
- 38 cases, half IMN, half plate + cement
- higher rates of pain relief with ORIF and cement
ORIF
Leukemia
Neuroblastoma
Wilm's
Last two usually occur in < 5 year age group
Bone scan is method of choice for screening for metastasis
Epidemiology
Most common form of cancer in children 30%
- ALL 5 x AML
- 3 : 100 000
History
Suspect in any child complaining of diffuse bone pain
Xray
Lytic transverse lines in epiphyses
- permeative infiltration of bone with periosteal reaction
- focal destructive lesions
- occasional diffuse sclerosis
Diagnosis
CBC
Blood smear
Bone marrow aspirate
Background
Tumour of sympathetic nervous system
- arises anywhere in the sympathetic nervous system or adrenal medulla
- 10% primary site not found
- malignant small round cell tumour
Usually present with abdominal mass and fever
Xray
Multiple destructive lytic lesions in any part of the skeleton
- often associated with periosteal new bone
- may be permeative
- skull lesions common
Diagnosis
Elevated serum / urinary catecholamines and VMA
Bone Marrow Aspirate
Background
Nephroblastoma
- arises in kidneys
- usually occurs in first 5 years of life
Associated with hemihypertrophy / Beckwith syndrome
Most present with abdominal mass
- may have abdominal pain
Diagnosis
Abdominal USS / CT
Management
Nephrectomy / chemotherapy
Ewings
Lymphoma
Osteosarcoma
Rhabdomyosarcoma
Retinoblastoma
1. Establish a differential
2. Stage locally and systemically
3. Biopsy
4. Definitive Treatment
Questions
- what do you think it is?
- is it benign (latent, active, agressive)?
- is it malignant (primary or secondary)?
1. Where is the tumour?
Flat bone / long bone
Epiphysis / metaphysis / diaphysis
Medullary canal / cortex
Eccentric in bone
2. What is it doing to the bone?
Expansion
Cortical erosion / breakthrough
Fracture
Permeative margins
Wide / narrow zone of transition
- narrow / can draw edge with a pen / good sign
- wide / infiltrative / bad sign
The best indication of the aggressiveness of a tumour is the transition zone or margin that surrounds the bone
3. What is the bone doing to it?
Periosteal reaction
- Codman Triangle / Sunburst / Onion Skinning
Reactive rim
- Sclerotic = Slow growing
- Ill defined = Fast growing
Margin
1. Moth eaten / permeative / ill defined / wide zone of transition / cortical or cancellous
2. Well circumscribed / narrow zone of transition / sclerotic rim
4. Are there any clues to its histological diagnosis?
Bone formation / Calcification
Soft tissue component
Radiolucent / ground glass
Matrix Osteoid / Chondroid / Myxoid / Collagen
FOGMACHINES
Fibrous dysplasia
Osteoid Osteoma / Osteoblastoma / Osteosarcoma
Giant cell tumour
Metastasis / myeloma
ABC
Enchondroma / Chondroblastoma / Chondrosarcoma
Hemangioma / HPTH
Infection / Intraosseous ganglion or lipoma / Infarct
Non Ossifying Fibroma / Neurofibroma
EG
Simple bone cyst / Synovial Proliferation
Age
- consider primary bone tumour < age 40
- consider metastasis > age 40
- consider EG < age 10
Malignant pain
- night time, severe, increasing
Trauma
Soft tissue mass = Aggressive lesion
Inflammation = Infection / Ewing's
Serum electrophoresis / Urine Bence Jones (Multiple Myeloma)
PSA - prostatic cancer
ESR - non specific (increased in infection / Ewing's / MM / lymphoma / metastasis)
ALP - increased in Osteosarcoma & Paget's
Calcium / PTH - think of hyperparathyroidism
Mammogram / Thyroid Ultrasound - metastasis
CT Chest / abdomen / pelvis - RCC, lung cancer, bowel cancer
Consider observation if lesion unchanged from at least 2 years ago
Purpose
- accurately define the extent of the disease
- prior to proceeding with biopsy and definitive treatment
CT
Best for assessing mineralisation & bony details
- benign bone tumours
- violation of cortex
- matrix mineralisation
- shows areas that plain X-ray visualise poorly i.e. Spine / Pelvis
MRI
Best for assessing soft tissue component
Assess
1. ST tumours
2. Cortical breakthrough / T2
3. Soft tissue extension / T2
4. Marrow involvement / intramedullary spread
- T1 with fat suppression
5. Relationship to NV bundle / T2
6. Joint & Epiphyseal involvement
7. Infection - rim enhancement on gadolinium
Advantage
- guides extent of treatment
- > 5cm margin on MRI / wide excision
Disadvantage
- may be oversensitive
- oedema vs tumour
Bone scan
Determines if lesion polyostotic v monostotic
- this aids with differential diagnosis
- will identify metastasis
False negative / cold scan
- inactive benign tumours
- myeloma / EG / melanoma
CT Chest / Abdo / Pelvis
Purpose
- identify primary tumour that may have metastasised to bone
- identify liver and lung metastasis
Benign - no need for biopsy
Uncertain or malignant - need for biopsy
A. To determine whether benign or malignant
B. To determine specific cell type
C. To determine grade
See Principles of Biopsy
See specific tumour articles
Theory
- want to traverse one muscle / one compartment
- keep away from NV bundle
- as a rule perform open biopsy through compartment the tumour is in
- this is the compartment that will require surgical removal in wide excision
- direct approach without going through muscle if possible i.e. tibia, distal ulna
Thigh
1. Lateral compartment ST tumour
- lateral approach
- through ITB
- through vastus lateralis / anterior to lateral intermuscular septum
2. Medial compartment ST tumour
- medial approach
- through gracilis
- keep away from NV bundle
3. Posterior compartment ST tumour
- posterior approach / transmuscular
Femur
1. Femoral head / neck
- depends if lesion benign or malignant
- tdranstrochanteric: for completely contained osseous tumour
- Watson-Jones: however if is malignant will consign patient to extra-articular resection
2. Subtrochanteric
- remember lesions here in elderly may be chondrosarcoma from enchondroma
- lateral approach
3. Femoral Shaft
- lateral through vastus lateralis
- anterior cortical window
4. Condyles
- medial or lateral approach
- incision through medial or lateral vastus
Popliteal fossa
Popliteal fossa / parosteal OS
- posterior approach
- go through hamstrings or gastrocnemius
- depending on whether lesion medial or lateral
Patella
Direct anterior
Tibial
1. Medial plateau proximal tibial bony tumour
- direct medial approach directly onto bone
2. Lateral plateau proximal tibial bony tumour
- through biceps femoris
- avoid CPN
3. Tibial shaft
- through tibialis anterior
4. Medial malleolus
- direct medial approach
5. Posterior distal tibia
- posterolateral approach
Fibula
1. Fibular head
- incision posterior fibular head
- expose and protect CPN
2. Fibular shaft
A. Direct lateral
- straight down to bone
- fibula / peroneals and nerve get taken in salvage
B. Posterolateral approach
3. Lateral malleolus
- direct lateral approach
Leg
1. Proximal posterior compartment ST tumour
- medial to tibia
- preserve anterolateral compartment
2. Proximal anterolateral compartment ST tumour
- direct approach through tibialis anterior
- will likely not be able to preserve CPN
Talus
1. Head and neck
- medial approach between T anterior and T posterior
- may need medial malleolar osteotomy
2. Body
- Ollier's approach
Calcaneum
Bony tumour
- direct lateral
- avoid medial NV bundles
Foot
1. Navicular / Medial cuneiform
- direct medial
2. Cuboid
- direct lateral
3. Intermediate cuneiform
- between EHL and EDC but away from dorsalis pedis
4. Lateral cuneiform
- lateral to EDC
5. Metatarsals / phalangeals
- dorsal approach
6. Soft tissue tumour
- medial or lateral as required
Iliac crest
- definitive surgery via ilioinguinal approach
- best to use iliac crest aspect of this approach
- can go medial or lateral to crest
Anterior column
- Watson - Jones through G medius
- avoid femoral NV bundle
Posterior column
- Kocher - Lagenbeck through G maximus
Pubis
- Pfannenstiel approach
Ischium
- lithotomy position
- detach adductor and hamstrings
Sacrum
Direct posterior approach
Humerus
1. Proximal humeral bony tumour
- direct lateral
- through deltoid muscle
- never deltopectoral (condemns patient to forequarter amputation)
2. Shaft
- modified Henry
3. Distal humerus bony tumour
- lateral longitudinal to capitellum
- medial approach to trochlea
Radius
1. Proximal bony tumour
- protect radial nerve at all times
A. Radial head: Kocher approach / through anconeus
B. Proximal third: Henry approach / take off supinator
C. Middle third: Henry approach / take off pronator teres
D. Distal third: Henry approach / take off pronator quadratus
2. Distal radius
- dorsal approach as salvage is always wrist fusion
- through second compartment / sacrificeable
Wrist / Hand
1. Carpus
- dorsal approach
2. Metacarpal / phalanges
- dorsal approach
- avoid volar to preserve NV bundle
Ulna
1. Proximal ulna bony tumour
- direct subcutaneous approach
- away from ulna nerve
2. Coronoid
- posterior approach with window for biopsy
3. Distal ulna bony tumour
- direct lateral approach between FCU and ECU
- down onto subcutaneous surface of ulna
Clavicle
Clavicle
- direct subcutaneous
Scapula
Acromion - deltoid split
Spine - transverse approach
Body - Judet posterior approach
Glenoid - posterior approach, through T major
Coracoid - deltopectoral approach
C1-2 bony tumour
- anterior retropharyngeal approach
- anterior to SCM
- resect submandibular gland and ligate duct
- CN XII superiorly
- between carotid sheath and larynx
- biopsy through longus colli
C3-T1
- Smith-Robinson approach
- vertical incision
- split longus colli
T2 - T12
- posterior approach and transpedicular
- open or CT guided
L1-L5
- anterior retroperitoneal approach
High grade tumours often sensitive to intensive chemotherapy
- OS
- Ewings
- MFH
Low grade often insensitive
- Chondrosarcoma
- Parosteal OS
1. Eradication of overt & micrometastasis
- OS 80% have micrometastasis
2. Reduce tumour locally
- makes limb salvage easier
3. Improve local control
- lesser role
- local control has no real impact on survival
Interferes with synthesis of
- DNA
- RNA
- Protein
Action
Non-specific
- all cells
Cell Cycle-specific
- proliferating cells
Cell Phase-specific
- portion of proliferating cells
1. Alkylating agents
- Cyclophosphomide
- Cisplatin
- Ifosfomide
2. Antitumoural Antibiotics
- Doxorubicin
- Bleomycin
3. Plant Alkaloids
- Vincristine
- Vinblastine
- VP-16 (Etoposide)
- Taxol
4. Antimetabolites
- Purine and Pyrimidine Antagonists
- Thioguanine & Mercaptopurine
- Cytarabine & 5-FU
- Methotrexate - Folate antagonist
Responsible for much of improvements in results
G-CSF
- 175 amino acid glycopn
- developed from E.coli recombinant DNA technology
- improves recovery by reducing neutropenic period
- neutropenia can be devastating in the more aggressive protocols
- G-CSF allows the dose to be increased further and achieve higher cell kill
Blood Products
- when needed
- i.e. platelets
N 5-formyl-tetrahydrofolate
- MTX rescue
- following very high doses
Leucovarin
- MTX rescue
Ondansetron
- serotonin antagonist
MACI pre op + G-CSF support
MTX
- high dose
- can see dramatic response
- blocks conversion folate ->tetrahydrofolate
- can cause renal failure
- alkylate urine and hydrate +++
- leucovorin rescue
- otherwise die very quickly
- doesn't suppress bone marrow to any great degree so use after an alkylating agent
- side effects related to levels
- mucositis and ulcers / pleuritis / conjunctivitis / hepatic and renal failure
Adriamycin
Cisplatin
- standard drug for OS
- alkylating agent
- direct DNA damage
- SE - emesis, renal and ototoxic
Ifosfamide
- new generation alkylating agent
- single most effective agent against sarcoma
- activated by hepatic P450 system
Adjuvant (Postoperative)
Neoadjuvant (Preoperative)
Standard strategy is neoadjuvant
- allows assessment of response early in disease
- restaging investigations after neoadjuvant chemotherapy
- imaging, histology
Advantage
- improves limb salvage
- allows planning of surgery
- re-stage after chemo
- prognostic
Measured by extent of tumour necrosis
- good response is > 90% necrosis
- poor response is < 90% necrosis
- response is best prognostic factor
Rosen in vivo response dictates outcome
- Grade 1 = no cell death
- Grade 2 = partial <90%
- Grade 3 = necrosis >90%
- Grade 4 = complete necrosis
1 & 2 < 50% survival
3 & 4 > 75% long term survival in OS and MFH
Using Cisplatin, Doxorubicin, MTX
Tumour cells develop cell membrane pumps to expel chemotherapy
Most commonly
- bone marrrow
- oral & GIT epithelium
Effects are
- myelosuppression
- stomatitis
- mucositis
- N & V
- anorexia
- infertility
- hair loss
All males store semen prior to chemotherapy
Females consider egg retrieval
Less predictable effects
1. Pneumonitis & Pulmonary fibrosis 2° Bleomycin
(blasts the lungs)
2. Cystitis 2° Cyclophosphamide
(cills the kidneys)
3. Nephrotoxicity 2° MTX & Cisplatin
4. Cardiotoxicity 2° Doxorubicin
(death to the heart)
5. Neurotoxicity 2° Cisplatin & Vincristine
Systemic
- neutropenia
- thrombocytopenia
- coagulopathy
Local
- cytotoxicity to tissue
- wound complications
- delayed bone healing
Improved 5 year survival from 20 - 80%
- improved ability limb salvage OT
- multi-agent treatment
- Rosen T10 protocol (MAC CAB)
- Methotrexate / Adriamycin / Cyclophosphamide / Cis-Platin / Actinomycin-D / Bleomycin
Pre-operatively
- 2 / 12 months
- 3 cycles 2 weeks apart
Restage disease
- repeat MRI
- may repeat CT Chest / Abdo & bone scan
Surgery
Post-operatively
- regimen continued for further 6-12/12
Previous treatment was surgery or radiotherapy
- dismal outlook
- < 15% 5 year survival
Combination with chemotherapy gives much better results
- 50% 5 year disease-free survival
- 70% 5 year overall survival
- 30% 5 year if present with metastasis
Multiagent neoadjuvant chemotherapy
- 3/52
- Vincristine / Actinomycin D / Cyclophosphamide / Adriamycin
- alternating with 3/52 of Iphosphamide / VP-16
Surgery performed when estimated that maximal response achieved
- usually at 3-4 /12
Mainstay of treatment is resection
- multiagent neoadjuvant chemotherapy improves 5 year survival from 50% - 75%
Primary treatment is surgery as tumour resistant to chemotherapy
- occasionally used for palliation but effects unclear
- hormonal agents may be effective
- i.e. HGH, somatomedin
Improved survival from 20% to 60% 5 year
- much poorer for metastatic disease
Treat as one disease
- controversial
- no clear evidence of long-term efficacy with chemotherapy
- exception is MFH and synovial sarcoma
Most important
Mitotic Figures
Necrosis
Next Important
Anaplasia
Pleomorphism
Atypia
- specimen fixed in formalin
- decalcified if contains bone
- embedded in paraffin
- water replaced with wax
- fine sections cut
- stained with Haematoxylin & Eosin
- Haematoxylin stains Protein blue
- Eosin stains Cytoplasm & Collagen pink
Van Gieson's
- myogenic tumours
Reticulin
- vascular tumours, clear cell sarcoma
- alveolar soft part sarcoma
Periodic Acid Shift
- Ewing's/ PNET
- Rhabdomyosarc
- Neuroblastoma
Melanin
- melanoma
Masson's Trichrome Stain
- presence of collagen = fibrosarcoma
Specimen fresh
- specimen frozen with liquid nitrogen
- fine sections cut
- similarly stained
Rationale
Identifies certain proteins
Technique
Slide prepared as above
- particular antibody-containing solutions put on slide
- antibody binds with antigen if particular protein present
- then another antibody with attached colouring agent put on slide
- binds to antigen-antibody complex if present
- thus stains if protein of interest present
Types IHC Stains
Keratin + / Vimentin -
- carcinoma
Keratin - / vimentin +
- sarcoma
Keratin + / Vimentin +
- synovial / epitheloid sarcoma
- adamantinoma
- osteofibrous dysplasia
- chordoma
S100
- Melanoma
- Schwann / Neural cells
- Ewings / PNET
Factor VIII
- vascular tumour
MIC2
- Ewing's, PNET
Actin
- muscle, myofibroblasts
Desmin
- muscle
Myoglobin
- skeletal muscle only
LCA (leucocyte common antigen)
- lymphoma
- haemopoietic lesions
Cytokeratin
- skin
- synovial sarcoma
- epithelioid sarcoma
Epithelial Membrane Antigen
- synovial sarcoma
- epithelioid sarcoma
NSE, GFAP, Neurofilament PR
- round cell tumours
Measure DNA content in each cell by flow cytometry
- quantify no cell with normal & abnormal amounts DNA
- N = 23 pairs (Diploid) or 46 total
Little benefit as
1. Not used to grade neoplasia
2. Not useful for prognosis
3. Can't diagnose tumour type
Rationale
- certain tumours have identified genetic abnormalities
Technique
- cells cultured
- halted in metaphase
- karyotyping performed
- chromosomal banding patterns identified
Examples
Ewings / PNET
- t (11, 22)
- EWS - FLI
Clear Cell Sarcoma t (12, 22)
Synovial Sarcoma t(X, 18)
Liposarcoma
Rhabdomyosarcoma
Infantile Fibrosarcoma
Trisomy 11, 17, 20
Rationale
Certain ultrastructural features differentiate tumour types
DDx PNET/ Ewing's / Neuroblastoma
Epithelial structures in carcinoma
Sarcomeres in Myosarcoma
Melanosomes in Melanoma
1. Provide representative sample
- to determine whether benign or malignant
- to determine cell line
- to grade lesion
2. Not compromise definitive treatment
Last step in evaluation / after staging
Don't perform definitive procedure immediately after biopsy unless
- pre-operative & Xray information characteristic
- fresh frozen section unquestionably confirms diagnosis
- i.e. ABC, GCT
Usually biopsy, then definitive OT later
Overall, open preferred
Open
Advantage
- more tissue
- lower sampling error
Disadvantage
- larger field to excise later
- higher local complications (i.e. infection, haematoma)
Needle Biopsy
Advantage
- less expensive / less risky
- smaller field to excise later
Disadvantage
- reduced accuracy 70-85% vs 95% with open
Indications
1. Homogenous tissue expected - Myeloma
2. Treatment unchanged by subtle differences - Soft Tissue Sarcoma
3. Diagnosis relatively certain - Metastasis
4. Access difficult - Spine, Pelvis
5. Expert histologist available
6. Patient not able to tolerate big surgery or GA
Complications biopsy tract
- wound contamination -> tumour recurrence
- wound dehiscence
- infection
- haematoma - always drain biopsies (haematoma spreads tumour)
Results
Mankin 1982 JBJS
- complication rate x 5~12 when performed by other surgeon / other hospital
- 60% major error in diagnosis
- 20% treatment compromised by biopsy
Mankin and Simon 1996
- musculoskeletal tumour society
- follow-up study from 1982
- results no different from previous study
- 597 patients 21 institutions
- rate of diagnostic error 17.8%
- problems with biopsy causing change in treatment to more difficult or complex procedure 19.3%
- change in outcome attributed to biopsy 10.1%
- 18 patients had unnecessary amputation
- errors, complications and changes in course and outcome
- 2 - 12x more common than if biopsy done in referring institute instead of treatment centre
- 19.3% of biopsies planned poorly
Most common errors
Transverse incisions in soft tissue tumours
Needle biopsies only 60% accurate compared to 76% with open biopsy
Conclusion
Not always possible to perform biopsy in treatment centre
- do so after review of case and imaging with tumour surgeon
- discuss optimum biopsy approach
Pre-operative
Tumour staging first / all imaging obtained
Images reviewed with experienced MSK radiologist
Treating surgeon does biopsy at treating hospital
- discussed with tumour centre if not possible
Ensure expert pathological facilities
- experienced MSK pathologist
- frozen section available
No pre-op antibiotics / infection always in DDx
Tourniquet
- no exsanguination
- release before closure and obtain hemostasis
Intra-operative
1. Approach
- plan with future OT in mind
- all aspects of biopsy tract must be excised later
- incision must be incorporated in definitive surgery
- violate one compartment only / trans-muscular
- incision is longitudinal, no undermining skin edges
- don't expose NV structures
- meticulous haemostasis
2. Biopsy
- round cortical windows / decreased stress-risers
- swab taken / tissue for M/C/S
- tissue for FFS / histology
- no closure until discussion with pathologist on phone
- ensure they have enough to make a definitive diagnosis / cell line / grade
3. Closure
- plug bone windows with PMMA / minimises tumour spread
- achieve haemostasis
- closure in layers
- drain exit site in line with and through wound
- subcuticular suture to skin
- firm dressing
- immobilise
Post operative
Very careful post op
- pathological fracture changes outcome
Team approach
- pathologist / radiologist / oncologists / radiation oncologist
- all results are reviewed to ensure correct diagnosis and management
Use of ionising radiation to damage DNA to prevent cell replication
Most rapidly replicating cells affected the most
Radiosensitive tissue
- high turnover tissue
- high blood supply
Give DXRT in incremental radiation
Produce free radical by breakup of H2O
- H2O -> H+ + OH-
- free radicals denature DNA
- damage DNA so that cell can't divide
- cell then dies without dividing
Particles
- bigger particle produces greater damage
- different particles have different RBE (Radiobiological effectiveness)
- each particle works the same way- free radical production
Both tumour & normal cells injured
- normal cells recover
- tumour dies
Need O2 for DXRT to work
- hyperbaric better
- unoperated bed better
1. Photons
2. Gamma Rays
Go through body / not absorbed as particles
- Cobolt 60 - Almost obsolete
- Iridium - Occasionally used in Brachytherapy
- Caesium - Used for Gynaecology tumours
- Radium - Now obsolete
3. X-Rays
- diagnostic 50-150 kv
- deep X-Ray Therapy - 300 kv
- linear accelerators - 4-24 mv
4. Particle beams
Electrons - Linear Accelerators
- particle beams via linear accelerator
- produce electron beams -> absorbed as particles
- depending on energy of beam can dial up depth of beam
- 6MeV - 20MeV
5. Beta - Rays
- electrons given off by ionised substance
- injected locally
- Strontium, Yttrium & Samarium
6. Neutron beams
- very damaging
- experimentally are producing heavy particle beams via cyclotrons as neutron beams
Fractionation
- 1 large dose vs 60 small doses
- curative / fractionation
- palliative / minimal fractionation
100 Centigray = 100 Rad = 1 Gy
Metastasis
- 1000 Centigray in 10 doses
Bone Tumour
- 6000 Centigray in 30 doses
Maximum possible dose with acceptable damage to normal tissue
- 60 Gy in 30 fractions over 6/52
- equivalent to 18 Gy in one dose
- fractionation decreases late effects on normal tissue
- increased differential between tumour & tissue damage
- allows repair between treament
Usually given 3/52 postoperatively
- allows wound healing
- minimum delay as tumour interference activates cells in arrest phase
Careful planning
- multiple fields
- minimum normal tissue damage
Short course with lower total dose
- 30 Gy in 10 fractions
- 3 CentiGy or 3 Rad or 0.03 mRad
Simple field set ups
- late morbidity less of an issue
- delays callus formation if pathogical fracture
- slows chondroid formation at fracture but not with osteogenesis
- 96% local remission
External Beam
Brachytherapy
- old method
- place radioactive agent down tube
- high risk to doctor giving treatment
- now use remote brachytherapy
Intrapoerative radiotherapy
- give dose to site at time of surgery
- give high dose with minimal local effects
Remote Afterloading
- pour radio-active agent down into tube
6 Week Rule
- start radiotherapy < 6/52 after OT
Preoperative
- better blood supply
- needs oxygen to effect cell kill
- shrinks tissue from neurovascular bundle
- may allow limb salvage
Disadvantage
- impairs healing
Postoperative
- usually preferred
- wait for wound to heal
- start within 6/52 otherwise repopulates with tumour cells
- also easier to identify site of tumour
100% side effects
Early
Erythema / Dry desquamation / Ulceration skin
Lymphopaenia
Telangectasia
Myelosuppresion
GIT effects
Late
Skin Fibrosis
Joint Contracture
Muscle Atrophy
Lymphoedema
Hair loss
Chronic bone changes / fracture
Osteoradionecrosis - eg AVN Femoral head
Transverse myelitis
Lung fibrosis
ST & bony hypoplasia in kids
- physeal arrest
Endocrine suppression
Infertility
Skin cancers
Sarcomatous change
No indication for preoperative treatment
May be used for
- unresectable
- palliation for metastasis
Very high radioresponsiveness
- but low curability
- effective if combined with chemotherapy
- surgery & chemotherapy have better results
Relatively radioresistant
May be used for
- recurrence
- inoperable disease
Effective for Plasmocytoma
Combined with chemotherapy for Multiple Myeloma
Indications
- doubt about surgical margins
- NV structures close to tumour
- 50 Gy DXRT preoperatively
- 10 Gy Brachytherapy postoperatively
Useful to give radiotherapy preoperatively for sarcomas
- because it develops a rind around the tumour
- makes it a lot easier to excise
- operate at about 6 weeks post radiotherapy
Stage 1 Benign inactive
Stage 2 Benign active
Stage 3 Benign aggressive
Stage I Low grade malignant
Stage II High grade malignant
Stage III Metastases to any site
Purpose
- guide prognosis
- guide surgical management
- guide adjunctive therapies
Compartments
Definition
A compartment is an anatomically confining space
- will resist tumour spread beyond its boundaries
Intra-compartmental (4)
- intra-osseous
- intra fascial compartments
- superficial to deep fascia
- par-osseous
Extra-compartmental
- extension beyond above
- pelvis
- popliteal fossa
- axilla
- cubital fossa
Latent / Inactive
Non-ossifying fibroma
- benign, intracapsular, no metastatic potential
- typical clinical course is unchanging or self-limiting
- tendency to self healing
Active
ABC
- characteristic is progressive growth
- benign, intracapsular, no metastatic
- X-ray and clinical appearance suggests active but contained growth
- without extracapsular penetration
5-10% local recurrence with curettage
- respond well to wide excision
Aggressive
GCT
- locally aggressive but no metastatic potential
- benign, extracapsular but intra-compartmental
- X-ray and clinically characterised by extracapsular penetration & destructive growth
10-20% recurrence after marginal excision
- may even recur after wide excision
- best treatment by excision with cuff of tissue
1A Low Grade Intra-compartmental
1B Low Grade Extra-compartmental
2A High Grade Intra-compartmental
2B High Grade Extra-compartmental
3 Metastasis
Low grade
- low metastatic potential
- parosteal OS
Treatment is surgery alone
- don't require systemic treatment
- tumour nodules in reactive zone but not beyond
- wide excision
High grade
- grow rapidly & metastasise early
- tumour nodules beyond reactive zone
- classis central OS
Treatment is surgery & systemic treatment
Tumour removal to gain local control & minimize recurrence while maintaining functional limb
1. Intralesional
Within lesion
- macroscopic tumour remains
2. Marginal
Within reactive zone
- microscopic tumour remains
3. Wide
Intra-compartment and outside of reactive zone
- tumour & cuff of normal tissue
Beyond reactive zone
- > 7cm level on Te99 scan
- > 5cm level on MRI
- may leave skip lesions behind
- hence MRI
- remove biopsy site
- may mean amputation
4. Radical
Extra-compartmental
- removal of all compartments that contain tumour
Amputation is not necessarily Radical
- radical resection possible with limb salvage
Exceptions
Skin & subcutaneous tissue
- wide margin is < 5 cm
- radical margin is > 5 cm
Extracompartmental lesions
- can't have radical exision of extracompartmental lesions
- no longidudinal barriers to extracompartmental spaces
Two compartments
- both compartments must be removed to achieve radical resection
- sometimes only practical way to achieve this is amputation
Contamination
- when lesion entered, wound contaminated
- if exposed tissues not removed, margin is intracapsular
IA | IB | IIA | IIB | |
Intralesional | 90% | 90% | 100% | 100% |
Marginal | 70% | 70% | 90% | 90% |
Wide | 10% | 30% | 50% | 70% |
Radical | 0% | 0% | 10% | 20% |
About 80 - 85% patients with OS, Ewing's, CS amenable to limb salvage
- must have same survival rates
- must not delay adjuvant treatment
- reconstruction should be enduring with minimal complications
- function should approach that achieved by amputation
PIN LEG
- pathological fracture
- infection
- NV bundle involvement
- LLD > 8 cm
- extensive muscle loss
- Good v poor biopsy
Absolute
1. Can't obtain wide margins
2. Major NV involvement
- vessel grafts are possible
- nerve remains at risk
3. Infection
Relative
1. Pathological fracture
- hematoma spreads tumour beyond accurately defined limits
- may necessitate amputate
2. Inappropriate previous biopsy
- contamination of other compartment
3. Significant skeletal immaturity
- predicted LLD > 8cm
- adjustable / growing joint replacements availiable
4. Extensive muscle involvement
- leave leg non functional
5. Medically unfit
Radical or wide resection
- extra-articular resection is preferred if a tumour is adjacent to or involves a joint
- prophylactic antibiotics
- no tourniquet if possible
- no eschmarc
- biopsy site excised
- tumour &/or pseudocapsule not visualised during procedure.
- distant flaps should not be developed until the tumour has been removed
- all dead space should be eliminated, & haematoma formation should be prevented
- surgical wound marked with clips for later radiatherapy
- motor reconstruction by regional muscle transfer
- adequate soft tissue cover by flap to avoid skin necrosis
Arthrodesis
Autograft (remove and irradiate)
Allograft arthrodesis
Allograft arthroplasty
Modular Endoprosthesis
Advantage
- early weight bear and rehabilitation
- lower infection rates than allograft
- no risk of non union like allograft
Types
- rotating hinge
- expandable if final LLD > 2cm
- modular
Contraindications
- < 8 years old
Complications
Early complications
- wound infection
- skin necrosis
- DVT
- neuropraxia
- instability
Late complications
- prosthesis breakage
- LLD
- lysis
- instability
- late infection
Expandable Prostheses
Lengthen 2cm every 18 months
- surgical procedure
- excise fibrous tissue to prevent joint stiffness and protect NV bundle
Average lengthening 9 cm
50% complication rate
Advantage
- biological reconstruction
Disadvantage
- incorporation is a slow and incomplete process
- 20% will fail within 5 years
Indications
- patient < 20 years old
Complications
- infection 11% (sometimes only salvageable by amputation)
- fracture 16% (up to 3 years later)
- joint instability
- non union (increased by chemo/DXRT)
- OA (15% at 10 years with osteochondral allograft)
Results
Intercalary > osteochondral
Intercalary
- 80% good results
- 30% non union at one osteosynthesis site requiring intervention
Osteochondral
- 73% good results
Allograft - prosthetic
- 77% good results
Concept
- creates a functional BKA
- superior to AKA
Advantage
- low complication rate
- very functional
Disadvantage
- high rate cosmetic dissatisfaction
- patients should meet others with same procedure
Indication
- young child in whom endoprosthesis has high rate failure
- wide resection about knee
- sciatic nerve preserved
Technique
- tibia rotated 180o
- fused to femur
Complications
- post operative vascular occlusion
- tibio-femoral pseudoarthrosis
Results
- patients can play sports
Usually very large osseous defects
- difficult
- associated with significant complications
- better suited as adjuvant to other procedures or for smaller defects
Advantage over allografts
- more rapid incorporation
- stronger initial construct secondary to graft hypertrophy
Disadvantage
- increased surgical time
- surgical site morbidity
- size limitations
- stress fractures
|
Limb Sparing |
Amputation |
Local Recurrence |
5 - 10% |
5% |
Survival |
70% |
70% |
Functional Outcome |
Good |
Good |
Initial Cost |
High |
Low |
Long term cost |
|
|
Outcome
- limb salvage often functionally better
- complication rate and incidence multiple surgery higher
Strange scapular tumour
- typically bilateral
- occurs in lat dorsi
Complain of lump which appears around scapula
Looks like muscle on CT
Benign
Shows marked amount of elastin
Benign aggressive
- most serious of all benign STT
1. Intra-abdominal
- association familial polyposis coli & Gardner's syndrome
- aggressive infiltration
- death from retroperitoneal extension
2. Extra-abdominal
Non-metatasizing locally aggressive STT
- often invasive locally
- similar to low grade fibrosarcoma
Classically arise chest wall
- also limbs, head & neck
2 types
- superficial fibromatosis - palmar & plantar
- deep fibromatosis
F > M
Average age 40 years
Mass most common
Stiff joint
Neurological compression
Mostly proximal - axilla & groin
Gross
Firm mass with white hard cut surface
- may infiltrate local muscle
Histology
Spindle shaped fibroblasts with plump nuclei & mildly eosinophilic cytoplasm
- often arranged in parallel rows
- separated by variable but large amount of collagen
- may have high degree of cellularity
- very few mitoses & no necrosis
Can infiltrate skeletal muscle at periphery
80% success
Intralesional excision
- 90% recurrence
Wide excision
- 50% recurrence
Tumour resection margin
- best prognosticator
- tumour margin clear > 2 mm
Radiotherapy alone
- used for inoperable tumours & after debulking
Cystic structure lined by a mature capsule of dense fibrous tissue
- contains thick viscous fluid with a high mucopolysaccharide content
- fluid is a myxoid degeneration of synovial fluid
Most common in young females
- peak age 15-30
- F:M = 3:1
Most common tumour in hand (2/3)
Unclear
Numerous theories
- synovial herniation through capsular defect with development one way valve
- synovial rest
Development
- in early stages, communicate with cavity of tendon or joint
- with time, connection obliterated by fibrous tissue
- become completely enclosed
- fluid becomes inspissated (thickened / dried)
Gross
- thin-walled cyst
- may be multiloculated
- easily separated from surrounding soft tissues
- contents clear, viscous & jelly-like
- arthrogram usually demonstrates joint communication
Histology
- wall of paucicellular fibrous connective tissue
- no true epithelial or synovial lining
- contents consist of hyaluronic acid / plasma proteins
Most commonly present with cosmesis issue
Appears suddenly or develop slowly
Subside with rest & enlarge with activity
Most common around hands & feet
Increased incidence with
- RA
- OA (eg Meniscal cyst)
Rupture of wall with multiple needle punctures
- instillation of xylocaine & celestone
- 50% recurrence
GA & tourniquet
- excision of lump in full
- attempt to locate and tie off neck
- may excise segment of capsule
Benign adipose tumour
Most common mesenchymal neoplasm
- arise from normal fat
- appears during adulthood
80% subcutaneous
- shoulder girdle & proximal thigh most common sites
- well circumscribed mobile, round masse
Durcen's Disease
- multiple lipoma subcutaneous disease
Same signal intensity as surrounding fat
Divided into 5 subtypes
1. Simple lipoma
2. Spindle Cell Lipoma
3. Pleomorphic Lipoma
4. Intramuscular & Intermuscular
5. Angiolipoma
Incidence
- most common mesenchymal tumour
- tumour of adulthood usually > 40
- multiple in 5%
- 80% of all lipomas
- shoulder & proximal thigh common site
Macroscopic
- well circumscribed
- round to ovoid masses
- 4-10cm long
- homogenous pale to bright yellow on cut surface
Microscopic
- same as normal fat
- sheets of mature fat cells ovoid to round in shape
- contain single fat droplet
- peripheral nucleus
- capillary like vessels are occasionally seen between lobules
- areas of myxoid change or dense fibrous trabeculae are sometimes seen
Painless firm nodule on neck & shoulder in middle aged men
Macroscopic
- encapsulated with a delicate fibrous membrane
- arise within the subcutaneous tissue
- on section may have white to grey myxoid areas
Microscopic
- mature fat cells
- variable number of benign spindle cells
- the spindle cells are uniform & arranged in parallel
- mitotic figures are rare
- occasional lipoblasts occur
Rare
Microscopic
- similar to spindle cell
- has pleomorphic fat cells
- multinucleated giant cells instead of spindle cells
Macroscopic
2 types
- well defined fatty tumour or
- ill defined infiltrative lesion
- unlike superficial lipomas these variants often don't have a capsule
- tend to encircle nerves
Microscopic
- characterized by sheets & nests of mature adipose tissue insinuating between bundles of muscle fibres
- the fat cells are not atypical, & lipoblasts never occur
Microscopic
- have areas of fibrous, myxoid or other connective tissues
- often see secondary changes of calcification & haemorrhage etc
- true lipoma never becomes malignant
An atypical lipoma can't be differentiated from well differentiated liposarcoma
- often become large & mimic soft tissue sarcomas
Treatment
Wide margin
- clinical setting & an adequate tissue sample are required to differentiate liposarcoma
Schwannoma
- benign tumour of nerve sheath
Less common than neurofibroma
- occurs in adults
- can occur along any peripheral nerve
- also can occur along a nerve root
Usually a large nerve
More common in forearm
Seen in NF 2
- acoustic Schwannoma
Usually located eccentrically within nerve
- compared with NF which are fusiform swellings of the nerve
Well encapsulated
- capsule consists of epineurium
- bulges from originating fascicles & pushes aside adjacent fascicles
Contain spindled Schwann cells
Arranged in alternating hypercellular (Antoni A) & hypocellular (Antoni B) regions
Antoni A
- spindle cells form short intersecting fascicles
- whorling pattern with palisading nuclei
- nuclei pallisade & align into columns
- Verocay Bodies - adjacent parallel columns of nuclei separated by fibrillar cell processes
Antoni B
- spindle cells twisted & haphazardly arranged
- separated by abundant myxoid ground substance
- may be dilated blood vessels
- more loosely arranged myxoid tissue
Immunohistochemistry
Positive
- Vimentin
- S 100 strongly +ve
- Leu-7
Negative
- Glial fibrillary protein
- Keratin
Loss of genes on Chr 22
Painful tender lump
- altered sensation or weak uncommon
- usually along flexor surface
- can increase & decrease in size
Soft cystic lump
- mobile transversely but not longitudinally
- strongly positive Tinel's
Show lesion on nerve periphery
Compared with NF which is in centre of nerve
Usually removed easily
- open capsule & enucleate with little or no injury to nerve fascicles
- shelling pea from pod
If uncertain of diagnosis, obtain fresh frozen section
Malignant degeneration occurs, but rare
Benign tumour of nerve & sheath tissue
Most common benign nerve sheath tumour
- associated with NF 1
- usually arises from small cutaneous nerves
1. Localised
- most common type
- usually solitary (90%) with no genetic association
- nil malignant transormation
Originate from very small branches of cutaneous nerve
- non encapsulated
- consist of twisted spindle cells arranged in fascicles
- accompanied by wire-like bundles of collagen / myxoid stroma
2. Diffuse
Uncommon
- proliferation of spindle cells, collagen & stroma
- permeates subcutaneous tissue & dermis
3. Plexiform
Pathognomonic of NF 1
Massive expansion of nerve by proliferating tumour cells
- may involve small cutaneous nerve
- ill-defined nodule
- may originate in large nerve
- elephantiasis or gigantism
10% malignant transformation
Contain proliferation of
- schwann cells
- perineural cells
- fibroblasts
Looks like bland but collagen rich fibrous tumour
- small to moderate amounts of mucoid material
- not encapsulated
S-100 stain
- far less intense than in neurilemmoma
Schwannomas / neurilemmoma
- contain only Schwann cells
Localised - painless, soft, mobile
Diffuse - plaque-like cutaneous mass
Plexiform
- ropey redundant mass
- feels like a bag of worms
- 50% of NF patients develop malignancy
1. Six or more café-au-lait spots (over 5mm in prepubertal individuals and over 15mm in postpubertal individuals)
2. Two or more neurofibromas of any type or one plexiform neurofibroma
3. Freckling in the axillary or inguinal region
4. Optic glioma
5. Two or more Lisch nodules (iris hamartomas)
6. A distinctive osseous lesion such as sphenoid dysplasia or thinning of the long bone cortex with or without pseudarthrosis
7. A first degree relative (parent, sibling, or offspring) with NF1 by the above criteria
Surgical Indications
- pain
- nerve dysfunction
- rapid growth
- suspicion of malignancy
Technique
- not easily separated from nerve
- excision usually involves partial resection of nerve
- if nerve small is sacrificed
- if nerve large and important need interposition graft
Surgical Indications
- persistent symptoms / pain & numbness
- features of malignancy
Features of malignancy
- enlarging
- new or increasing pain
- perform biopsy
Technique
- excision difficult
- entering nerves usually sacrificed
- graft if needed
STS composed of malignant lipoblasts
Common
- 10% of STS
- second only to MFH
Occurs almost exclusively in adults
Males age 40-60
Can be multiple origin -> examine patient
Rarely arise from lipoma
Many MFH's classified as liposarcoma in past
Liposarcoma S-100 +ve
MFH negative to immunohistochemistry
Thigh / retroperitoneum / popliteal fossa / inguinal region
Almost always subfascial
- often between muscles or perivascular
Painless mass or mild dull ache
No systemic complaints
Usually present late when tumour large
- especially retroperitoneal
- no pain as tumour deep
Deep to fascia / heterogenous
Pattern different to other STS
- 1/2 metastasise to lung
- 1/2 unusual non lung sites - retroperitoneum / mediastinum
Depends greatly on subtype & grade
Gross
May quite large especially in retroperitoneal region
- well circumscribed & multilobulated
- soft, firm or rubbery
- colour based on mix of fat / myxoid / fibrous
- high grade = Necrosis
Histology
Diagnose by identifying typical lipoblasts
- signet ring cells
- contains 1 or 2+ round cytoplasmic fat droplets which form sharp, scalloped indentatons on the nucleus
Liposarcoma vs Atypical Lipoma
Often difficult to differentiate low grade well differentiated liposarcoma from atypical lipoma
- if subfascial & non homogenous on MRI
- treat as STS
- even if biopsy suggests benign
- high sampling error with biopsy
5 Types Histology
- treatment depends on grade & histology
1. Well-Differentiated 30%
- low grade 70% 5 year survival
- lipoma like
- risk of distant metastasis very low
- often recur after local excision
- death only with retroperitoneal metastasis
2. Myxoid 50%
- low-grade 70% 5-year survival
- delicate plexiform capillary network
- translocation between 12 and 16
3 . Round Cell 10%
- high-grade 40% 5-year survival
- sheets poorly differentiated rounds cells
4. Pleomorphic 20%
- high-grade 40% 5-year survival
- multivacuolated lipoblasts
5. Dedifferentiated
- due to heterogenity may be confused with other lesions
- myxoma / pleiomorphic lipoma/ myxoid chondrosarc / melanoma
- metastatic adenocarcinoma especially RCC
Results
Longhi et al J Clin Oncol 2008
- retrospective review
- compared preRT / postRT / chemo and no adjuvant treatment
- postop RT had best 5 year disease free survival at 82%
Malignant Fibrous Histiocytoma
Characterised by heterogenous population of pleomorphic spindle cells
- organised in a characteristic storiform or "starry night" pattern
Cell of origin unknown
- primitive mesenchymal cell
- allowing both features of a macrophage (hence histiocyte)
- and collagen producing cell (hence fibroblast)
Most common STS
- > 50 years old
- diagnosis largely replaced fibrosarcoma
Becoming less common again
- many being reclassified
- basis of immunohistology
- turning out to be poorly differentiated liposarcoma or malignant muscle tumours
Aggressive
- majority Grade II
Rare cases of multicentric tumours reported
Soft Tissue
Arise from primitive mesenchymal cells
Bone
A. Primary 80%
- arise from bone mesenchymal cells
- exhibits both histiocytic & fibrous properties
B. Secondary 20%
Occur in abnormal bone
- Paget's disease
- bone infarct 10%
- post DXRT
- multiple osteochondromatosis
Most common in thigh
- 85% deep to fascia
- thigh > leg > arm > forearm
Retroperitoneal > 15cm
Bone
- knee / femur / tibia / humerus
"An aggressively enlarging, deep, and surprisingly mildly symptomatic soft tissue mass characterizes soft tissue MFH"
Normal except for ST shadow
Large soft tissue mass
- arising from muscle
- patchy non-homogeneous areas
Bone
- metaphyseal purely lytic lesion
- ill-defined margins with cortical destruction
- no intra-tumour calcification
- may be seen arising from area of bone infarction
Gross
Solitary or multinodular
- margin usually discrete
- has fish-flesh appearance
- colour varies with proportion of stromal to cellular elements
- myxoid variant has white-grey, soft mucoid tumour lobules
- 5% undergo extensive necrosis & haemorrhage
Histology
Basic cellular constituents
1. Fibroblasts in Storiform pattern
2. Histiocyte like cells with vacuolated cytoplasm and evidence of phagocytosed hemosiderin, lipofuscin etc
3. Mesenchymal cells
4. Giant cells
5. Inflammatory cell infiltrate not uncommon
Local control / wide resection if able
Radiotherapy if doubt about margins
Chemotherapy for metastasis
Best in I A/B
- 50% 5 year survival
- 85% if < 5 cm
50% metastasis on diagnosis
50% recurrence rate
- local recurrence is aggressive
- causes significant morbidity
- doesn't alter overall survival
Leimyosarcoma
Fibrosarcoma
Clear cell sarcoma
Epitheliod sarcoma
Neurosarcoma
Tumour of smooth muscle
- ? arises from vein wall
- very rare
- can arise from Leiomyoma
Most common in elderly
Usually found in deep soft tissues
- especially retroperitoneum
- extremities
- GUT
- can see in uterine fibroids
Associated with NV bundle
Most common peripherally in
- groin
- popliteal fossa
Aggressive - early metastasis
As for STS
- wide resection & DXRT
Malignant spindle cell neoplasm
- produces a sparse to moderate amount of collagenous matrix
- has no other matrix differentiation
Since MFH, true Fibrosarcoma <10% STS
Primary tumour of mid-adults
- typically adult 20-60 yrs
M = F
Usually lower limb
Infantile & Congenital types exist
- better prognosis
- distal
FS v Fibromatosis
- the site, age, & histological findings must be carefully evaluated
- difficult to distinguish low grade fibrosarcoma from fibromatosis.
Gross
Arise from deep fascial or aponeurotic elements
- small tumour - well circumscribed
- larger - infiltrative
Histology
Principle cell the fibroblast
- spindle cell capable of producing collagen
- collagen easily identified in well differentiated specimens
Two varieties
1. Well differentiated
- uniform spindle cells in fascicles
- herring bone pattern
2. Poorly differentiated
- poor fascicular pattern
- increased pleomorphism
- many mitoses
- difficult to pick from MFH & both behave the same anyway
Immunohistochemistry
Masson's trichrome stain confirms the presence of collagen
AKA Malignant Melanoma of the soft tissue
Small tumour
Arises in conjuction with tendons & aponeuroses
- common around foot & ankle 50%
- young patients 20 - 40 years
Characteristic translocation
- t(12:22)
Young male with tumour in foot and ankle
- think of clear cell sarcoma or synovial sarcoma
Metastasis
- lymphatic & haematogenous spread occurs
- enlarged local nodes require dissection
Gross
- solitary or multinodular firm mass
- attached to tendons /aponeuroses
- rarely > 6cm
- white to brown on its cut surface
Histology
Distinct fascicles & nests of spindle cells
Uniform plump spindle cells
- pale cytoplasm
- contain glycogen
- melanin is present in 50%
Immunohistochemistry
Fontana preparation for Melanin
PAS for Intracellular Glycogen
Odd small STT
- often misdiagnosed as benign ganglion
- ganglions occur in typical places
- if not, suspect more sinister diagnosis
50% arise forearm / wrist
- number 1 Sarcoma of hand
Can arise in the dermis
- can present with nodule or ulceration
- simulates a cutaneous lesion eg granulomatous dermatitis
Tends to lymph node spread
Young adults compared with other STS
Gross
- arises in deep tissues especially near tendons, fascia
- often firm & multinodular
- occasionally central necrosis
Histology
Nodules or granuloma like collections of epithelioid cells
Epithelioid cells
- large cells
- deeply eosinophilic cytoplasm
- may transform to spindle cells
Characteristic feature is that of diffuse infiltration of tendon & fascial structures by elongated nests of tumour cells
Arise from peripheral nerves
10% of STS
50% have NF
NF
- 10% life risk & increases with age
If not associated with NF then occur in older patients
Painful mass
- previously painless, small stable tumour
- now painful
- enlarging
Often presents with neurological symptoms (arise on nerve)
- pain / paraesthesia / weakness
Pressure
- elicit pain & parasthesia in distribution of nerve
Site
- Brachial plexus
- lumbosacral plexus
- major nerve trunks - especially the sciatic nerve
The MRI does not reliably distinguish a benign neurofibroma from one that has undergone transformation to a neurosarcoma
Gross
Fusiform or bulbous swelling of a peripheral nerve
- usually deep
- infiltrates as it enlarges
- grey to white in cross section
- areas of necrosis
Histology
Basic pattern of intersecting spindle cell fascicles
- herringbone
- very similar to fibrosarcoma & leiomyosarcoma
- wavy nuclei
- pallisading pattern ± whorled
- rare epithelioid variant
- similar melanoma or carcinoma
Most are high grade malignancies
- five year survival rate < 50%
- regional metastases to LN uncommon
Lung and bone are the commonest sites of distant metastases.
Because of their association with the major neurovascular bundles, the vast majority of the lesions present in Stage II-B
Solitary neurosarcomas have a better prognosis than those associated with neurofibromatosis 1
1. MFH
2. Liposarcoma
3. Rhabdomyosarcoma (Paediatric)
4. Synovial Sarcoma
5. Leiomyosarcoma
6. Fibrosarcoma
1. Adipose / LS
2 Fibrous / FS
3. Fibrohistiocytic / MFH
4. Muscle / Leiomyosarcoma / Rhabdosarcoma
5. Vascular Tissue
- haemangioendothelioma / angiosarcoma / kaposi's sarcoma
- malignant glomus / malignant haemangiopericytoma
6. Synovial / Synovial Sarcoma
7. Nerve / Malignant Schwannoma
- neurofibrosarcoma
8. Autonomic Ganglia / Neuroblastoma
9. Bone / Cartilage - Extraskeletal OS & CS
10. Uncertain
- alveolar soft part sarcoma / epitheliod sarcoma / extra-skeletal ewing's
- clear cell sarcoma / malignant melanoma of soft parts
Size
Grade including metastases
Malignant ST lesion
Benign ST lesion
- vascular (hemangioma, AVM, lymphangioma, glomus)
- neurogenic (NF, schwannoma)
- muscular (leiomyoma)
- fibroblastic (desmoid tumour, fibromatosis)
- fat (lipoma)
- simple cyst
PVNS / synovial chondromatosis
MO
FB
Malignancy - melanoma, metastatic
Present as painless ST mass
- increasing in size
- becoming painful
Very rare to have systemic signs
Occurs 30 - 60 years
DDx calcification
- hemangioma
- MO / HO
- synovial sarcoma / liposarcoma
Aim
- detects ST tumours
- determines anatomical extent
- determines depth
- compartments / NV bundles
- characterises tumour
- plans resection / biopsy / approach
Locally
- MRI for soft tissue component
- MRA for vessel involvement
- +/- CT if intra-osseous
Systemic
- bone scan to detect intraosseous spread
- CXR and CT chest as per usual
40% in lower limbs
50% in limbs
Remainder head neck and trunk
Act similar to sarcomas of bone
Exceptions
- usually remain intracompartmental
- significant incidence of lymphatic involvement in synovial and alveolar soft part sarcoma
Malignant | Benign | |
Size | > 5 cm | < 5 cm |
Location | Deep to fascia | Superficial to fascia |
Feel | Soft, mobile, nontender | Firm, fixed, tender |
Depends on the usual histological findings
- mitoses, pleomorphism, necrosis, nuclear atypia
- can be difficult
Exception
- synovial sarcoma
- usually high grade
American Joint Committee on Staging of STS 1993
Grade | Size | Spread | |
IA | Low | < 5cm | |
IB | Low | > 5cm | |
IIA | Intermediate | < 5cm | |
IIB | Intermediate | > 5 cm | |
IIIA | High | < 5 cm | |
IIIB | High | > 5cm | |
IVA | Any | Lymph node | |
IVB | Any | Metastasis |
Modification 1997
Only low and high grades
Size
Depth
- important to prognosis
- i.e. subfascial
Now 5 year survival 50 - 80%
- combination wide resection and DXRT
Local recurrence doubles metastasis risk
Death from
- primary diseases / local recurrence
- lung / bone metastasis
Unfavourable
- > 5 cm
- deep / extracompartmental
- inadequate excision
- histological high grade
Wide Resection + DXRT
- wide resection for local control
- DXRT to prevent local recurrence
- role of chemotherapy in adult STS uncertain
Addition of DXRT has allowed limb salvage surgery without recurrence
Irradiate all tissue at risk
- use filters & radiosensitisers
- local morbidity has decreased significantly in recent times
Pre-op DXRT
- 50 Gy in 2 Gy fractions
- higher doses than carcinoma
- shrinks tumour & makes resection easier
- increased complication rates
- surgery after 2-4 wks to allow skin to settle
Post-op Brachytherapy ~ 10 Gy
No conclusive studies demonstrating efficacy of chemotherapy
Exception
- paediatric rhabdomyosarcoma
- high grade sarcomas
- treatment for lung mets (50% response rate)
For 10 years
- CXR every 3/12 for 2 years then 6/12 for 5 years
- physical examination of site for recurrence
- MRI site if concern
Local recurrence
- surgical excision & adjuvant DXRT
Lung Metastasis
- chemotherapy +/- surgical excision
- 20% survival at 5 years
Different entity
- histololgically small cell
- different response to treatment
- good response to chemotherapy
- respond to surgical measures better as are fibrous based
Tumours
- rhabdomyosarcoma
- soft-tissue Ewing's
- PNET
- neuroblastoma
Malignant tumour of striated muscle
Juvenile variety arises from mesenchyme
Most common malignant ST Tumour in children (< 15 years)
- groin, head & neck
Recently, most adult rhabdomyosarcs reclassified as MFH
Four types "BEPA"
1. Embryonal
Most common type 2/3
- arises in groin & head & neck > Urinary Tract & Retroperitoneum
- not common in extremities
- occurs in age < 10 years
- very aggressive
Histology
- poorly differentiated rhabdomyoblasts
- limited collagen matrix
- small blue round cell
DDx
- undifferentiated carcinoma / small cell OS / neuroblastoma / lymphoma / PNET / Ewing's
- IH desmin / myoglobin
- EM cross striations
2. Alveolar
More common in extremities than trunk
- older
- occurs in age 10-25 years
- ggressive
- histology similar to embryonal
- well differentiated round cells arranged in alveolar pattern separated by thick fibrous septa
3. Botryoid
"Bunch of Grapes"
- uncommon
- ccurs in hollow viscus
- particularly the bladder
- grape like clusters of round cells beneath the mucosal lining of hollow organs
- EM studies: sarcomere formation and cross striations
4. Pleomorphic
Rare
- occurs in adults
- deep portions of the extremities
- arises skeletal muscle
- dark red lobulated mass
Histology
- spindle shaped cells with marked variation in size / shape
- bizarre gigantic cells
- cells can resemble a wrist watch
DDx
- MFH
- EM / IHC
Genetics
Characteristic translocation
- t(2:13)
Neoadjuvant Chemotherapy
- exception to usual management for STS
Wide surgical resection
- total excision of involved muscle
DXRT
- if resection not possible or incomplete
Depends on resection & stage
- complete resection, 85% 5 year survival
- macroscopic residual disease or distant metastases, 50% 5 year survival
4th most common STS
- 10-35% of STS
Peak age 3rd-4th decade
- rare in children
Cellular characteristics suggest tumour arises from primitive synovial cells
- rarely actually occurs within joint
Occasionally metastasis to lymph nodes (5-7%)
- like Epitheloid Sarcoma
- feel nodes in examinaiton
Classically show mineralization
- see on knee X-ray
Most common STS of foot
Rarely intra-articular
Deep soft tissues
- often centered on tendons, bursa and joints
- head, neck & trunk 15%
- extremities 50% / knee
- hands & feet 10% / often mistaken for ganglion
May have calcification or ossification in tumour
Malignant ST tumour
Benign ST tumour - hemangioma / AVM
Malignant bone tumour - OS
Myositis Ossification
Clear cell sarcoma
Rhabdomyosarcoma
TB! - Calcified lymph node
Knee
- heterogenous mass, not communicating with joint
DDx Baker's cyst
- semimembranosus
- communicates with joint
- between semimebranosus tendon and medial head gastrocnemius
Difficult to grade
- all considered high grade
- more extensive calcification suggests better prognosis
A. Biphasic Type
- classic pattern
- contains 2 distinct cell types
- epitheliod cells which resemble adenocarcinoma
- form gland like structures lined by cuboidal cells
- malignant spindle cells
B. Monophasic Type
- as common as classic biphasic
- spindle cells only
- difficult to DDx from fibrosarcoma
Have a characteristic translocation
- t(X:18)
Limb salvage may be possible
- amputation preferred in hand & foot
Post operative chemotherapy
70% 5 year survival rate
Metastases occur in 50%
Poor prognosis
- local recurrence
- inadequate resection
- large size / monophasic / mets
Better prognosis
- heavily calcified
- <5cm
Proliferative synovial condition
- characterised by synovial villi
- centre is lipoma
Most common in the knee
- massive synovial swelling
- large effusion
Can lead to early degenerative change
Unknown
- postulated to be related to minor knee trauma
MRI
- synovial proliferation
- signal similar to surrounding fat
Arthroscopy
- yellow brown polypoid / frond like villous synovitis
PVNS
Synovial Chondromatosis
1. Arthroscopic Debridement
2. Open Debridement
3. Radionuclide Injection
- Yttrium 90
- not proven to work
- risk skin necrosis
Pigmented Villo-Nodular Synovitis
- benign inflammatory process that arises in synovial tissues
- contains significant amounts of hemosiderin
Age: 20 - 50
Sex: M > F
A. Diffuse
- throughout joint synovium
- more difficult to treat / excise fully
B. Localised
- just one area of synovium
- i.e. suprapatella / medial or lateral gutter
Major joints
- knee, hip, shoulder, and ankle
- has been observed in all joints
Usually mono-articular
- occasionally multiple joints
In aggressive cases, PVS may involve adjacent bone
The cause is unknown
Theories
1. Recurrent hemarthrosis
- cavity of the involved joint is recurringly filled with old unclotted blood
- hemosiderin is a prominent gross and histological finding
- may lead to
2. Inflammatory process
- marked synovitis
- no virus, bacteria or other inflammatory stimulant has been demonstrated
3. ? Neoplasm
- there are scattered reports of distant metastases to the lungs and other organs leading to death
The process is intermittently progressive
- over a period of several months or years
- diffuse synovial involvement
Progressive destruction of the articular cartilage and subchondral bone
- results in severe degenerative arthritis
Extensive soft-tissue extension occurs
- may produce peripheral neuropathy by neurovascular bundle involvement
In aggressive cases, PVNS may involve adjacent bone
- pathologic fracture secondary to subchondral bone invasion is occasionally seen
- especially in the femoral neck
Intermittent joint effusion
Modest discomfort
Antecedent trauma
- often recounted but difficult to relate to the development of PVNS
Blood tinged / xanthochromic
- in absence of trauma
- highly suspicious of PVNS
Soft tissue swelling
Arthritic changes
Bone destruction
- invasion of adjacent metaphyseal cancellous bone
- may be suggestive of neoplasm
Increased uptake +++
Characteristic T2
- heterogenous picture
- high intensity signal from vascular component
- low intensity signal from hemosiderin
Hemosiderin has low signal intensity on TI and T2
Assess involvement of knee areas
- suprapatella
- medial and lateral gutters
- posterior compartments
- femoral notch
Nodular
Diffuse
Haemophilia
Lipoma arborescens
Synovial chondromatosis
Complete synovectomy
- dissecting the synovium and intermediate layers
- preserve deep fibrous layers and ligaments
- need to remove all affected synovium for best results
- meticulous surgical technique required
Options
Open
- posterior recess difficult to access
- or if extracapsular
Arthroscopic
- often need posterior cannulas / portals
- takes up to 2 hours
Kim et al Clin Orthop Research 2000
- 11 patients with localised PVNS of the knee treated arthroscopically
- no recurrences at 2 - 4 years
Chin et al JBJS Am 2002
- treatment of recurrent PVNS in 40 patients
- repeat surgery with post op radiation synovectomy or DXRT if residual disease
- best outcomes with complete surgical excision of all disease
Chondroid Metaplasia of synovium affecting large joints
Nodules of hyaline cartilage
- formed in the subsynovial layer of joint capsules
Rare lesion
Most common in 20's and 30's
Sex: M > F (2:1)
Monoarticular
Any synovial lined joint, tendon or bursal cavity
Marked predilection for large joints
Knee (70%) > Hip > Elbow > Shoulder
Primary
Secondary
- more common
- preexisting OA/RA/AVN/Charcot/TB
Primary
Mesenchymal cells in joint capsule (subsynovial layer) become Chondroblasts instead of Fibroblasts
- form nests of cartilage
- nests grow & protrude into joint
- covered by synovium
- eventually become pedunculated into joint
- connected by synovial stalk
Then break off & lie free in joint as cartilaginous LB
- Continue to grow in joint 2° synovial diffusion
- can undergo secondary calcification and ossify
Secondary
Patient with shearing chondral injury
- cartilage cells can seed synovium and continue to grow
Central necrotic area that may be calcified
- peripheral ring of viable chondrocytes
- disorganized chondrocytes with cellular atypia
- can be difficult to pick from chondrosarcoma
Milgram 1977 JBJS
Phase 1 - Early; Synovitis, no loose bodies
Phase 2 - Transitional ; Synovitis & loose bodies
Phase 3- Late ; Loose bodies, no synovitis
Pain & swelling
Loss of ROM
Locking & giving way
Multiple loose bodies
Calcified lesions
Loose bodies in suprapatellar pouch
Synovial Proliferation
Subsynovial masses
- same signal intensity as cartilage
Synovial proliferation
- localised or generalised
- can see cartilage growing from synovium
Multiple loose bodies +++
Early surgery to prevent secondary degeneration
Biopsy
Options
1. Arthroscopic
2. Open without dislocation
- leave synovium on ligamentum teres
3. Open with dislocation
- lower recurrence
- risk AVN
- Ganz anterior open dislocation
Results
Boyer et al JBJS Br 2008
- arthroscopic debridement in 111 patients, follow up average 6 years
- 20% required subsequent repeat arthroscopy
- 38% required subsequent open synovectomy
- 20% went on to require THR
De Sa et al Arthroscopy 2014
- systematic review of arthroscopic hip debridement
- 7.1% recurrence rate
- minor complication rate 1%
Lim et al JBJS Am 2006
- 21 cases treated with open synovectomy
- 8 treated with arthrotomy alone with 2 recurrences
- 13 treated with surgical dislocation with no recurrences
- recommend dislocation with extensive disease
Results
Ogilvie-Harris et al Arthroscopy 1994
- 13 patients with generalised disease
- 5 treated with removal loose bodies only
- 8 with synovectomy
- lower recurrence in synovectomy group
Results
Lunn et al JBJS Br 2007
- 15 patients, half primary and half secondary
- arthritic changes present in 8 prior to treatment, 11 after
- arthroscopic synovecotmy + open biceps tenotomy if this area involved
- good pain relief but no improvement in ROM