Imaging of pigmented villonodular synovitis.

Pigmented villonodular synovitis (PVNS) is a rare, benign, idiopathic proliferative disorder of the synovium that results in villous and/or nodular formation in joints, tendon sheaths, and bursae. The disease can be localized or diffuse. Patients with this condition typically present with symptoms of mild discomfort and associated stiffness of the involved joint; however, the spectrum of presentations is broad. Diagnosis of PVNS can be clinically difficult, and plain radiographs are usually nonspecific. Magnetic resonance (MR) imaging is a highly diagnostic modality in characterizing PVNS when it contains hemosiderin deposits exhibiting low signal intensity on all MR image pulse sequences. This article discusses the presentation, pathology, differential diagnosis, diagnostic modalities as well as various treatment options of PVNS.