title: Localized pigmented villonodular synovitis of the anterior cruciate ligament of the knee: an exceptional presentation of a rare disease with neoplastic and inflammatory features.
abstract: Pigmented villonodular synovitis (PVNS) is a rare condition, most commonly involving the knee joint. PVNS is locally aggressive and can invade and destroy surrounding soft tissue and bone, leading to anatomical and functional deterioration of the affected joint. Localized PVNS is an unusual presentation of the disease, generally consisting of a nodular lesion protruding into the articular cavity. Localized PVNS of the knee can mimic other joint disorders which may pose a challenge for a correct diagnosis. Given the locally aggressive behavior of PVNS, prompt identification and excision of the lesion are instrumental to avoid complications. Here, we report a rare case of localized cystic PVNS involving the anterior cruciate ligament of the knee in a 32-year-old woman with persistent knee pain, in whom magnetic resonance imaging was inconclusive. The diagnosis was achieved via arthroscopy and histology. We also present a concise review of the literature on this pathological entity as well as a discussion on the differential diagnosis between localized PVNS and other intra-articular cystic lesions.
authors.forename: M
authors.initials: M
authors.lastname: Galli
authors.forename: V
authors.initials: V
authors.lastname: Ciriello
authors.forename: A
authors.initials: A
authors.lastname: Menghi
authors.forename: C
authors.initials: C
authors.lastname: Perisano
authors.forename: G
authors.initials: G
authors.lastname: Maccauro
authors.forename: E
authors.initials: E
authors.lastname: Marzetti
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007249:Inflammation / Q000175:diagnosis / Q000473:pathology; D016173:Macrophage Colony-Stimulating Factor / Q000096:biosynthesis; D008279:Magnetic Resonance Imaging; D009369:Neoplasms / Q000175:diagnosis / Q000473:pathology; D035583:Rare Diseases / Q000175:diagnosis / Q000473:pathology; D013586:Synovitis, Pigmented Villonodular / Q000175:diagnosis / Q000473:pathology*
chemical_list: D016173:Macrophage Colony-Stimulating Factor