title: Synovial sarcoma of the cauda equina.
abstract: Primary synovial sarcoma originating from the cauda equina is extremely rare. Only one case, involving an 11-year-old girl, has been reported. The authors describe the case of a 23-year-old woman with a primary synovial sarcoma of the cauda equina.   The patient visited a local hospital and described a 2-month history of low-back pain. She was referred to the authors' hospital for further evaluation. On physical examination, she had a straight-leg raising result of 70° bilaterally. Motor examination revealed Grade 4/5 strength in the bilateral extensor hallux longus muscles. There was normal sensation to light touch and vibration in the lower extremities. Sagittal Gd-enhanced T1-weighted MR imaging demonstrated an intradural, extramedullary, and uniformly enhancing mass that extended from L-3 to L-4. The mass was totally resected and adjuvant local radiation therapy was administered. Reverse transcriptase polymerase chain reaction (RT-PCR) of a paraffin-embedded tissue sample revealed SYT-SSX fusion transcripts, and the diagnosis of synovial sarcoma was confirmed. Five and a half years after surgery, the patient is free of local recurrence and metastatic disease. The RT-PCR detection of SYT-SSX fusion transcripts played a key role in establishing the diagnosis of synovial sarcoma of the cauda equina. Complete resection of the mass with adjuvant local radiation therapy proved to be effective.
authors.affiliation: Department of Orthopaedic Surgery, Juntendo University School of Medicine, Tokyo, Japan. yoza@juntendo.ac.jp
authors.forename: Ikuho
authors.initials: I
authors.lastname: Yonezawa
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Saito
authors.forename: Daishi
authors.initials: D
authors.lastname: Nakahara
authors.forename: JongHwa
authors.initials: J
authors.lastname: Won
authors.forename: Takuro
authors.initials: T
authors.lastname: Wada
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kaneko
mesh_terms: D002420:Cauda Equina / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008648:Mesoderm / Q000473:pathology; D014411:Neoplastic Stem Cells / Q000473:pathology*; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D011128:Polyradiculopathy / Q000473:pathology* / Q000601:surgery; D013584:Sarcoma, Synovial / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D012983:Soft Tissue Neoplasms / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D055815:Young Adult
chemical_list: D015514:Oncogene Proteins, Fusion; C116512:SYT-SSX fusion protein