Recurrent giant cell tumor of the flexor digitorum superficialis tendon sheath
The most common soft tissue lesion of the hand and wrist is ganglion cyst followed by giant cell tumor of the tendon sheath (GCTTS). The former is usually seen along the dorsum of the wrist and the latter is usually seen within the fingers 2. GCTTSs are rare benign lesions of giant cells usually seen arising from tendons and hence the characteristic location related to joints. They are closely related to pigmented villo-nodular synovitis and termed by some as extra-articular pigmented villo-nodular synovitis 4,5. They may contain hemosiderin and may enlarge to destroy adjacent bone 3.
The affected patients are usually in their 20-40 years of age; with no definite sex predilection 3.
The most common presentation is a firm, non-tender mass related to a hand or wrist joint 1.
The most helpful diagnostic procedure is MRI 4. The best diagnostic combination is: soft-tissue tumor near a joint or along a tendon sheath showing intermediate signal intensity on T1 and T2W images with hemosiderin deposits 3,5. MRI appearance may include low to intermediate signal with low signal septa on T1W images, low to intermediate with low signal hemosiderin foci on T2W images and may be inhomogeneous on both. Additional imaging findings may include convex bowing toward the skin from the tendon sheath, flexor or extensor tendon relation and adjacent osseous compression erosion 2,5.
The treatment of choice is complete excision of the lesion. Unfortunately, there is a high rate of lesion recurrence, which is reported to be 10-20 % (9-44%) 4,6. Incomplete excision and leaving behind satellite nodules is considered as the most important factor determining recurrence 6. Therefore, a balanced compromise between total resection of tumor and maintenance of tendon function must be achieved 1. There has been a recent suggestion to use fine needle aspiration cytology (FNAC) as a primary diagnostic tool. Preoperative diagnosis of GCTTS was attained using FNAC and may help in preoperative planning to prevent recurrence 6.
The case was pathologically proved.