Pigmented villous nodular synovitis

Pigmented villonodular synovitis (PVNS) is a proliferative lesion of the synovial membrane that often presents as a localized nodule. The mass may originate from the joint synovium, tendon sheath, fascial layer, or ligament tissue. The lesions appear as painless soft tissue masses, usually at the fingers and toes. It can also be found in other joints (especially the knee joint) and tendon sheaths. Onset of a single joint is a rule of this disease, but there are rare multiple joint lesions.