Giant cell tumor of the distal phalanx : A case report

This repon describes" giant cell tumor of the dista l phalanx of the founh digit of the right hand in a 43-year-old man. With clinically 3 months of pain and soft tissue mass on enlarged tip of the digit, the conventional radiographs showed markedly expansi le, geographic osteolytic lesion, breaking of the cortex of the distal phala1lX. Ultrasound represented hypoechoic lesion with contiguous soft tissue nudu1c. The thinning and paflial deslrllction of bony cortices with soft tissue extension of distal phalanx was demonstrated on CT scan. Microscopy showed a lesion composed of prolife ration of polygonal 111ononuclealCd stromal cells and evenly distributed multinucleated, osteoclast-like giant cells. Some area comprised a characteristic of secondary fibrous hstiocytoma. We describe the clinical, radiographic, and histologic features of [his benign bone tumor in a very unusual loc(ltion emphasizing the dirferential diagnosis with giant cell repi;lrative granuloma; a more common txmy reaction in the hand.