Benign Soft Tissue Tumours

Assume all malignant until proven otherwise

 

1. Ganglion

 

Foot GanglionAnkle ganglion MRI

 

Mucoid degeneration of a joint capsule or tendon sheath

- may fluctuate in size or disappear

- firm subcutaneous nodule

- may be painful, especially if compressed

- often transilluminate

 

Treatment

- observe

- multiple aspirations / cortisone injections

- surgical excision

 

Surgical excision

- need to find neck

- may arise from AKJ / STJ / T post tendon

- tie off neck or excise segment of capsule

 

Foot Ganglion 1Foot Ganglion 2Foot Ganglion Neck 1

 

Foot Ganglion Neck 2Foot Ganglion Neck 3

 

2. Plantar fibromatosis

 

Most common soft tissue tumour in the foot

- see other notes

 

3. Fibroma

 

Discrete nodule of well differentiated fibroblasts

- on sole or dorsum

- slow growing

- pain uncommon

- usually subcutaneous, firm, not attached to skin

 

Treat

- local excision if required

(recurrence rare)

 

DDx

- Fibrosarcoma

- Plantar fibromatosis

 

4. Giant cell tumour of the tendon sheath

 

Ankle Giant Cell TumourAnkle Giant Cell Tumour

 

Usually in tendon adjacent to ankle (can be anywhere)

- well defined firm nodule with an obvious capsule

- not always painful

- pain with direct pressure

 

Treatment

- observe (may involute)

- surgical excision (recurrence rare)

 

5. PVNS

 

Common around the ankle or midfoot

- may involve multiple bones

- usually in young adults

 

X-ray

- may show bony erosions

- brown villonodular synovium

 

Treatment

- excision include complete synovectomy

- recurrences common but not all symptomatic

- DXRT if severe

 

6. Lipoma

 

Most common on dorsum

- subcutaneous

- soft feeling / mobile / grape like

- painless unless compressed

 

Treatment

- marginal excision

(local recurrence rare)

 

7. Neurilemmoma

 

Benign schwannoma

- well encapsulated solitary tumour

- originates from nerve sheath

- slow growing

- nerve fibres spread over its surface

- painful if compressed or causes compression

 

MRI

- hyperintense rim on T2

 

Management

- separate nerve fascicles

- excise neurilemmoma

- marginal excision

- attempt to preserve normal nerve fibres

 

8. Neurofibroma

 

Singular or multiple

- extend along course of the nerve 

- 1/2 not associated with NF

 

Often local pain especially with compression

- may affect distal nerve function

- malignant change rare in solitary lesion (occurs with NF)

 

MRI

- target sign

- can be seen with neurilemmoma

 

Treatment

- tumour arises from within the nerve

- excision usually cause further loss of function

 

9. Solitary Hemangioma

 

Present with episodes of dependent swelling

- often after local trauma

- diffuse edges / can be difficult to palpate

 

Diagnose on MRI

- hyper-intense on T2 FS

 

Treatment

- only needs excision if limits function

- often incomplete - recur

 

10. Glomus tumour

 

Presents as painful toe, sensitive to cold

- pain with local pressure

- usually subungual

 

X-ray

- may scallop adjacent bone on x-ray

 

Treatment

- marginal excision for pain

 

11.  Synovial osteochondromatosis