A Case Report of Giant Cell Tumor of the Flexor Tendon Sheath in Index Finger

INTRODUCTION: Giant cell tumor of the tendon sheath (GCTTS) is an uncommon benign soft tissue tumor of unknown etiology. It is seen more commonly in hand than ankle and foot. It presents as a painless and palpable swelling. Its diagnosis is mostly established by histopathology after surgical resection, although pre-operative imaging and fine-needle aspiration cytology (FNAC) support its suspicion. Herein, a case of GCT of flexor tendon sheath of the right index finger is reported due to its rarity. CASE REPORT: A 46-year-old female presented with complaints of swelling over the front of the right index finger for 1½years. The swelling was spontaneous, painless, and very slowly progressive. Examination revealed a 2 cm × 1.5 cm firm swelling situated on the palmar aspect of the right index finger over distal part of middle phalanx and proximal part of the distal phalanx. Swelling was well defined, having smooth surface, uniformly firm consistency and could be moved sideways easily. X-ray of the hand showed localized soft tissue shadow in the involved area without any bony involvement. Ultrasonography of the finger showed soft tissue mass. FNAC examination reported the swelling as GCTTS. Excisional biopsy was done. Histopathology showed typical features of GCTTS. CONCLUSION: GCTTS should be kept as a differential diagnosis in soft tissue tumors of hand in adults. FNAC followed by excisional biopsy is diagnostic and curative, but the patient should be followed up for detecting and managing recurrences.