- Discussion:
- GCT of tendon sheath are not really tumors but reactive lesions, which are similar to PVNS;
- they do not always arise from the tendon sheath but may arise from the synovium;
- it is the second most common benign hand tumor next to ganglions;
- age > 30 years;
- diff dx:
- clear cell sarcoma;
- fibroma of tendon sheath;
- epithelial inclusion cyst;
- fibrous histiocytoma of skin (dermatofibroma);
- epithelial sarcoma
- Clinical Features:
- it is usually seen on the palmar surface of digits, especially at PIP of index and long fingers;
- may or may not be painful;
- most of these tumors are well circumscribed but some are grow diffusely (which can make excision difficult);
- always perform a digital Allen's test of the affected digit (since this may affect surgical excision);
- Histology:
- lesion consists of multinucleated giant cells, polygonal mononuclear cells, and histiocytes (may contain abundant hemosiderin or lipid).
- Radiographs:
- 20% of cases show extrinsic cortical erosion, which may be a risk factor for recurrence;
- Operative Excision:
- they are frequently encapsulated, but not as well encapsulated as lipomas;
- it is slow growing and recurrs in 10-20% of excisions;
- therefore, even w/ meticulous dissection, recurrence is common;
- if there is radiographic cortical erosion, then consider removing cortical shell as well;
- malignant transformation has not be reported despite multiple recurrences
Pigmented villonodular synovitis (giant-cell tumor of the tendon sheath and synovial membrane). A review of eighty-one cases.
Giant cell tumor of tendon sheath with intraosseous invasion: a case report.