&Pigmented Villonodular Synovitis=Pigmented villonodular synovitis (PVNS) is a rare but well recognized proliferative lesion of synovial tissue. It is characterized by hypervascular proliferative synovium containing multinucleated giant cells, macrophages and hemosiderin. Progressive nodular disease near or in the joints limits function and may destroy adjacent bone. Although most believe PVNS to be an inflammatory process, others consider it a benign neoplasm. PVNS occurs in two forms: a diffuse form that involves the entire synovium and accounts for in the majority of cases, and a localized form that involves a discrete section of the synovium. PVNS almost always involves a single joint; most commonly the knee but also the hip and finger synovial structures, while involvement of the shoulder, foot, and ankle is rare.