PIGMENTED VILLONODULAR SYNOVITIS - REVIEW WITH ILLUSTRATIVE CASE-REPORTS

The histopathology of PVNS is characterized by giant cells, hemosiderin, variable collagenization, foam cells, and a histiocytic infiltrate. In the diffuse form of PVNS, the synovium displays numerous gross microscopic villi. It is unlikely that repeated trauma or hemorrhage are primary etiologic factors, and the disease is not a malignancy. Histiocytic proliferation may play a fundamental role in pathogenesis. PVNS occurs in two forms, localized and diffuse. Localized PVNS presents either as asymptomatic, solitary, nodular tenosynovitis, frequently on the digits of the hand, or as an intraarticular nodule, usually at the knee, with symptoms of internal derangement. Diffuse PVNS occurs as a monarticular arthritis with chronic swelling and stiffness; lobulated synovial thickening may be found on physical examination. Laboratory data are normal, except for a preponderance of red blood cells on synovial fluid analysis. Plain films show soft tissue swelling without periarticular osteopenia, and usually without joint space narrowing. Occasionally, x-rays in both the diffuse and localized forms of PVNS also show nonmarginal osseous cysts, either single or multiple. In DPVNS, arthrography may reveal a suggestive picture of multiple filling defects. Definitive diagnosis requires examination of tissue. In the differential diagnosis it is imperative not to confuse PVNS for a synovial sarcoma, in order to avoid unnecessarily radical surgery. PVNS is generally treated with surgical excision, either locally or, in diffuse disease, with synovectomy. Recurrences, which are frequent, are treated with repeat surgery, or, occasionally, radiotherapy. Both natural history and optimal therapy are unknown. © 1979.