title: Tumor-like meniscal cyst.
abstract: A 50-year-old woman presented with a 5-year history of mild pain in her right knee, which had increased over the last 2 years. A palpable mass over the anterolateral aspect of the knee was obvious and the last 3 months she was experiencing locking episodes with consequent knee effusion. The differential diagnosis was driven between meniscal cyst, pigmented villonodular synovitis, synovial sarcoma, synovial chondromatosis, and aneurysm. After a diagnostic arthroscopy, the lesion was excised by a limited lateral arthrotomy. The pathologic findings revealed a synovial cyst. Intra-articular synovial cysts are uncommon, nonsymptomatic, and mostly incidental findings on magnetic resonance imaging (MRI) and arthroscopy. This lateral meniscus synovial cyst (2.5 x 2.5 cm) was enlarged within the intracondylar notch and produced disabling knee symptoms. The peculiarity of this lesion was the tumor-like appearance: its large size, the progress of symptoms, and the multilobulated, nonhomogenous signal on the MRI scan. One year postoperatively, the patient is asymptomatic and the MRI obtained at 6 months revealed no remnant of the fully excised cyst.
authors.affiliation: Department of Orthopaedics, University of Thessaly, Larissa, Greece. roidis@in.gr
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Roidis
authors.forename: Vasilios
authors.initials: V
authors.lastname: Zachos
authors.forename: George
authors.initials: G
authors.lastname: Basdekis
authors.forename: Michael
authors.initials: M
authors.lastname: Hantes
authors.forename: Lubna
authors.initials: L
authors.lastname: Khaldi
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Malizos
mesh_terms: D001182:Arthroscopy / Q000379:methods*; D003560:Cysts / Q000175:diagnosis* / Q000601:surgery*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology; D008592:Menisci, Tibial / Q000000981:diagnostic imaging / Q000601:surgery*; D008875:Middle Aged; D010146:Pain; D010147:Pain Measurement; D011859:Radiography; D000070600:Tibial Meniscus Injuries