title: Pigmented villonodular synovitis presenting as a popliteal cyst.
abstract: A rare case is described of giant swelling of the soft tissue around the knee joint. A large popliteal cyst was present, the fleshy walls of which penetrated the muscle layers of the calf. The place of arthrography in diagnosis is stressed. The yellow-brown mass was confirmed histologically to be pigmented villonodular synovitis. The mechanism of formation of a popliteal cyst is discussed. The differential diagnosis and treatment are reviewed briefly: our preference is for radical surgery.
mesh_terms: D000328:Adult; D003560:Cysts / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D006801:Humans; D007592:Joint Diseases / Q000000981:diagnostic imaging*; D007719:Knee Joint; D008297:Male; D011859:Radiography; D013585:Synovitis / Q000000981:diagnostic imaging*; D013586:Synovitis, Pigmented Villonodular / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery