[Pigmented villonodular synovitis of joints. Apropos of 16 cases. Surgical aspects. Contribution of nuclear magnetic resonance imaging].

This study of 16 cases of pigmented villonodular synovitis of joints treated by the same surgical team involved 6 cases of the localized or nodular form and 10 cases of the diffuse form. The knee was the commonest joint involved (12 cases), with involvement of the hip (3 cases) and foot (1 case) being rarer. Bone invasion is usual when the joint is narrow (hip, foot) but is rarer in the knee where joint capacity is greater (5 cases out of 12). Clinical symptomatology is rarely typical. Hemarthrosis, the most suggestive sign, was found in only two cases out of twelve. While the final diagnosis must always be based upon histology, great help may be provided by modern techniques such as arthroscopy, computed tomography and above all MRI, the presence of hemosiderin being shown by a low signal in T1 which decreases even further in T2. Treatment is based upon surgical synovectomy, with advanced osteoarticular lesions requiring joint replacement.