Unveiling the Enigma: Uncommon Hand Giant Cell Tumor within the Tendon Sheath.

Introduction: Giant cell tumor of tendon sheath (GCTTS), also known as tenosynovial giant cell tumor or pigmented villonodular tenosynovitis, is a rare benign soft-tissue tumor with an unclear cause. It is the second most frequent soft-tissue tumor in the hand after ganglion cyst.

Case Report: We described a female patient, age 19, who has had a 3 cm × 2 cm firm swelling on the palmer aspect of the right second metacarpal region for 7 years.