title: Intra-articular calcifying synovial sarcoma mimicking synovial chondromatosis.
abstract: A case of intra-articular calcifying synovial sarcoma of the right knee joint in a 27-year-old man is reported. Prior to admission the patient had been suffering pain in the right knee for 5 years. Plain radiographs showed multiple calcified densities in the anterior aspect of the right knee closely mimicking synovial chondromatosis. Histological examination revealed that the lesion was a synovial sarcoma with extensive calcification subjacent to the synovial surface. Although intra-articular calcifying synovial sarcoma is very rare, it is important to be aware of the fact that synovial sarcoma, as well as synovial chondromatosis, can be present as a calcified lesion in the joint cavity.
authors.affiliation: Department of Pathology, Faculty of Medicine, University of Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ishida
authors.forename: T
authors.initials: T
authors.lastname: Iijima
authors.forename: S
authors.initials: S
authors.lastname: Moriyama
authors.forename: C
authors.initials: C
authors.lastname: Nakamura
authors.forename: T
authors.initials: T
authors.lastname: Kitagawa
authors.forename: R
authors.initials: R
authors.lastname: Machinami
mesh_terms: D000328:Adult; D002114:Calcinosis / Q000000981:diagnostic imaging / Q000473:pathology; D015838:Chondromatosis, Synovial / Q000000981:diagnostic imaging* / Q000473:pathology; D003937:Diagnosis, Differential; D006801:Humans; D007592:Joint Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D011859:Radiography; D013584:Sarcoma, Synovial / Q000000981:diagnostic imaging* / Q000473:pathology