Giant cell tumor of the bone presenting as swelling of the thumb.

We describe a giant cell tumor in a 74-year-old man who presented with pain and swelling in the left thumb. Radiographs of the left hand showed some lytic changes at the tip of the thumb. Magnetic resonance imaging suggested the diagnosis of giant cell tumor, which was later confirmed by biopsy. A good treatment response was achieved with disarticulation of the interphalangeal joint and amputation of the distal phalanx of the left thumb.