title: Bilateral diffuse pigmented villonodular synovitis of the knee.
abstract: Pigmented villonodular synovitis (PVNS) is a proliferative disease of synovial tissue characterized by lipid-laden macrophages, multinucleated giant cells, and hemosiderin deposits. PVNS presents either in a localized form with minimal rates of recurrence after surgical resection or in a diffuse form with an expansive growth pattern showing formation of osseous erosions and extra-articular manifestation. In the diffuse form high recurrence rates occur as a result of the challenge of achievement of total synovectomy. Typically only one single joint, being the knee in 80% of cases, is involved with diffuse PVNS. Reports of bi- or multiarticular manifestation are at best rare. Here, a case of a 16-year-old girl with bilateral diffuse PVNS of the knee allows discussion of diagnostic and treatment considerations.
authors.affiliation: Department of Orthopaedics, Uniklinik Balgrist, Zurich, Switzerland.
authors.forename: Georg
authors.initials: G
authors.lastname: Klammer
authors.affiliation: Department of Orthopaedics, Uniklinik Balgrist, Zurich, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Betz
authors.affiliation: Department of Radiology, Uniklinik Balgrist, Zurich, Switzerland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Delaloye
authors.affiliation: Department of Orthopaedics, Uniklinik Balgrist, Zurich, Switzerland.
authors.forename: Mazda
authors.initials: M
authors.lastname: Farshad
authors.affiliation: Department of Orthopaedics, Uniklinik Balgrist, Zurich, Switzerland.
authors.forename: Koch P
authors.initials: KP
authors.lastname: Peter
mesh_terms: D000293:Adolescent; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D012008:Recurrence; D000074402:Synovectomy; D013583:Synovial Membrane / Q000528:radiation effects; D013586:Synovitis, Pigmented Villonodular / Q000175:diagnosis* / Q000628:therapy*; D015021:Yttrium Radioisotopes
chemical_list: D015021:Yttrium Radioisotopes