GCT of tendon sheath

 

GCT of tendon sheath

Synonyms: 

Giant cell tumour of the tendon sheath 

Tenosynovial giant cell tumour

Pigmented villonodular tumour of the tendon sheath (PVNTS)

Localised or focal nodular synovitis.

They are usually seen as localized, single, slow-growing, subcutaneous soft tissue nodules, with or without pain on local examination, very common in hand and wrist, encountered during 3rd to 5th decades with slight female predilection.

On MRI, well defined ovoid lesion with low signal on T1 and T2 images, mild to moderate enhancement on post contrast, may show pressure erosion of adjacent bone, or rarely can invade the bone mimicking an intraosseous lesion on imaging.

Actually they thought to arise from the tendon sheath but unclear whether they represent neoplasms or just reactive masses. Intra articular GCT involving larger joints also very common as in this case. 

Histolopathogically identical to pigmented villonodular synovitis (PVNS), composed of fibroblasts and multinucleated giant cells, foamy histiocytes, and inflammatory cells on a background fibrous matrix.

Being benign local surgical excision usually suffices with local recurrence of nearly in 10-20% of cases requiring more extensive surgery with or without radiotherapy.