Pigmented villonodular synovitis (PVNS) is a benign proliferative disorder of the synovium of unknown etiology. PVNS usually affects young adults and generally is a monoarticular disorder. The knee is the most commonly involved joint and patients typically present with chronic swelling, pain, and limitation of motion. Pathologic features include hyperplastic synovium, hemosiderin-laden macrophages and synovial lining cells, and a hemorrhagic effusion. The bone scan findings in a case of surgically proven PVNS involving the knee joint are presented. Correlation with US, CT, and MRI provided complimentary diagnostic information in the evaluation of this rare disorder.
From the Departments of Radiology and Nuclear Medicine, Tripler Army Medical Center, Honolulu, Hawaii