Nodular pigmented villonodular tenosynovitis.

Pigmented villonodular tenosynovitis is a proliferative disorder of the synovium that can involve the joints, tendon sheaths, and bursae. There are two histologically similar lesions of pigmented villonodular tenosynovitis--nodular pigmented villonodular tenosynovitis and diffuse pigmented villonodular tenosynovitis. The authors present a case involving nodular pigmented villonodular tenosynovitis, which is the more rare form of these two lesions.