title: Pigmented villonodular synovitis presenting as a baker cyst.
abstract: Pigmented villonodular synovitis (PVNS), a rare hyperproliferation of the synovial lining, commonly mimics other conditions. As a result, the diagnosis may remain elusive, as the classic signs of tenderness and effusion are not specific. Occasionally, PVNS presents as a popliteal cyst, which may divert attention from intra-articular pathology. In this article, we describe a case of PVNS that presented with a popliteal cyst as the chief problem report. In other cases PVNS presented as a popliteal cyst, and evidence was reported of PVNS within the cyst stalk and presumable intra-articular involvement. Our case did not present this way. We recommend that the diagnosis of PVNS be considered in young adults who present with a popliteal cyst.
authors.affiliation: Department of Orthopaedic Surgery and Sports Medicine, Temple University, Philadelphia, Pennsylvania, USA. rtosti@temple.edu
authors.forename: Rick
authors.initials: R
authors.lastname: Tosti
authors.forename: John D
authors.initials: JD
authors.lastname: Kelly
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000473:pathology* / Q000601:surgery; D011151:Popliteal Cyst / Q000175:diagnosis* / Q000601:surgery; D013586:Synovitis, Pigmented Villonodular / Q000175:diagnosis* / Q000601:surgery