Pigmented villonodular synovitis : MRI

35 year old patient on MRI shows Fluid in the knee joint with extension into the suprapatellar bursa and medial/lateral recess, along with areas of enhancing synovial thickening extending into the semimembranous-gastrocnemius bursa (bakers cyst). There are focal areas of T1/T2 hypointensity in the anterior and posterior compartments, possible hemosiderin loose bodies. Synovial thickening shows T2 hypointense appearance. These findings are suggestive for pigmented villonodular synovitis.

Pigmented villonodular synovitis is a rare benign proliferative condition affecting synovial membranes of joints, bursae or tendons resulting from possibly neoplastic synovial proliferation with villous and nodular projections and haemosiderin deposition. PVNS is most commonly monoarticular (~70% knee joint) but occasionally it can be oligoarticular.