Extraarticular pigmented villonodular synovitis of the distal forearm: a case report.

Extraarticular pigmented villonodular synovitis (PVNS) is very rare in the distal forearm. There has only been one previous case report of this disease in the extensor tendons of a child. We report a case of PVNS of the distal forearm that presented as two nodules over the radial aspect and a separate nodule on the ulnar aspect beneath the flexor carpi ulnaris tendon. Surgical exploration revealed an extensive extraarticular PVNS over the first and second dorsal compartment extensor tendons. On the anterior aspect it extended in the deep plane between the flexor tendons and the pronator quadratus and encased the radial artery completely. Complete excision of the tumour with the radial artery was done.