Diffuse pigmented villonodular synovitis of the shoulder: a case report.

Pigmented villonodular synovitis (PVNS) of the shoulder is an uncommon disorder with unknown etiology. It is characterized by synovial proliferation and hemosiderin deposition into the synovial tissues of the affected joints. PVNS affects mainly the knee joint and shoulder involvement is rare. There are only 12 cases of shoulder involvement reported in the English-language literature. A case of PVNS of the shoulder with simultaneous rotator cuff tear is presented and the literature is reviewed.