Pigmented Villonodular Synovitis

Chapter 68 on pigmented villonodular synovitis (PVNS) reviews the clinical features, pathology, and imaging characteristics of PVNS. Epidemiology and treatment are briefly discussed. Diffuse intraarticular PVNS, localized intraarticular PVNS, and localized extraarticular PVNS, also referred to as giant cell tumor of the tendon sheath, are discussed. PVNS is considered to be a benign neoplastic disorder. Joints, tendon sheaths, and bursae may be involved. The knee is the most common location of the intraarticular form. The characteristic MRI finding is low signal intensity synovial proliferation or mass with blooming from susceptibility artifact on gradient echo images, secondary to the presence of hemosiderin.