Cystic synovial sarcomas: imaging features with clinical and histopathologic correlation.
OBJECTIVE
To characterize the radiological and clinicopathologic features of cystic synovial sarcoma.


METHODS
Seven patients with primary cystic synovial sarcoma were evaluated. Computed tomography (CT) and magnetic resonance (MR) imaging were undertaken at the first presentation. The diagnosis of synovial sarcoma was made on the basis of histological examinations followed by molecular analysis. Radiological and clinicopathologic findings were reviewed.


RESULTS
CT showed well-defined soft tissue mass without cortical bone erosion and invasion. Calcification was seen at the periphery of the mass in three cases. T2-weighted MR images showed multilocular inhomogeneous intensity mass in all cases, five of which showed fluid-fluid levels. On gross appearance, old and/or fresh hematomas were detected in six cases. In the one remaining case, microscopic hemorrhage in the cystic lumen was proven. Four cases had poorly differentiated areas. In five cases prominent hemangiopericytomatous vasculature was observed. Histologic grade was intermediate in one tumor and high in six. One case had a history of misdiagnosis for tarsal tunnel syndrome, one for lymphadenopathy, two for sciatica and two for hematoma.


CONCLUSIONS
All cystic synovial sarcomas demonstrated multilocularity with well-circumscribed walls and internal septae. Synovial sarcoma should be taken into consideration in patients with deeply situated multicystic mass with triple signal intensity on T2-weighted MR imaging.
Nakanishi
Hirofumi
H
Department of Orthopedic Surgery, Osaka Medical Center for Cancer and Cardiovascular Diseases, 1-3-3, Nakamichi, Higashinari-Ku, 537-8511 Osaka, Japan. h-nakanishi@mvf.biglobe.ne.jp
Araki
Nobuhito
N
Sawai
Yuka
Y
Kudawara
Ikuo
I
Mano
Masayuki
M
Ishiguro
Shingo
S
Ueda
Takafumi
T
Yoshikawa
Hideki
H
D000293:Adolescent; D000328:Adult; D044963:Biopsy, Fine-Needle; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D002648:Child; D003937:Diagnosis, Differential; D005260:Female; D005534:Foot Diseases / Q000000981:diagnostic imaging / Q000473:pathology; D006119:Groin / Q000000981:diagnostic imaging / Q000473:pathology; D006615:Hip / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D007564:Japan; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012189:Retrospective Studies; D013584:Sarcoma, Synovial / Q000000981:diagnostic imaging / Q000473:pathology*; D012983:Soft Tissue Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D013223:Statistics as Topic; D013581:Synovial Cyst / Q000000981:diagnostic imaging / Q000473:pathology*; D013848:Thigh / Q000000981:diagnostic imaging / Q000473:pathology; D014057:Tomography, X-Ray Computed