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)
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
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
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
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
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
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
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
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
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