Pigmented villonodular synovitis of the wrist invading bone--report of a case.

Pigmented villonodular synovitis of the wrist joint invading adjacent bones rarely occurs. A case in which synovitis invaded the carpal and metacarpal bones at the ulnar aspect of the wrist is described. The invasion of multiple bones by the tumor and its histologic hypercellularity in this case caused concern because of its aggressive behavior. However, review of the literature on pigmented villonodular synovitis arising at the wrist and invading adjacent bones and follow-up of our patient confirmed its benign character.