Pigmented villonodular synovitis. An immunohistochemical study on 103 cases

Pigmented villonodular synovitis is a common lesion of the synovial lining of joints and tendon sheats. It is not considered as a true neoplasm but as a reactive lesion. Diffuse and nodular forms are possible. 103 cases of pigmented villonodular synovitis were tested for alpha-1-antitrypsin, lysozyme, ferritin, S-100 protein and vimentin using immunohistochemical techniques. These markers are not significantly present in these lesions, which represent only a reactive pattern of normal synovial elements.