[Etiology and pathogenesis of synovitis villonodosa pigmentosa].

Articular pigmented villonodular synovitis is a benign synovial disease of unknown etiology. It is a proliferative disorder of the synovium that can involve the joints, tendon sheaths, and bursae. There is a predilection for involvement of the lower extremities, particularly the knees. There are two histologically similar lesions of pigmented villonodular synovitis: "nodular" and "diffuse" pigmented villonodular tenosynovitis. The typical clinical course consists of progressive and painful swelling of the involved joint. Cystic erosions without sclerosis and invasion of adjacent bone from intra-articular synovial lesions are the typical roentgenographic manifestations. The surgical treatment of the lesions is discussed. A review of the literature is given and our own material on 47 patients is presented to illustrate the different features of the disease.