Clinical presentation:
45 year old male, brought-up in the tropics, with a deformity of his thumb.

The tip of the left thumb and its terminal phalanx is completely missing. There is soft tissue swelling with a destructive lesion of the proximal phalanx of the right thumb. The distal section of the proximal phalanx is fragmented and the process extends to widen the interphalangeal joint. Bone density is normal. There is no disuse osteoporosis. There is some acro-osteolyis with erosison of the tips of the distal phalanges of the fingers. Subluxations have occurred at the proximal interphalangeal joints. The phalanges appear denser than normal. The cortex of the metacarpals appears to encroach on the diaphyseal medullary space.