title: Synovial sarcoma of nerve.
abstract: Tumors of peripheral nerve are largely neuroectodermal in nature and derived from 2 elements of nerve, Schwann or perineurial cells. In contrast, mesenchymal tumors affecting peripheral nerve are rare and are derived mainly from epineurial connective tissue. The spectrum of the latter is broad and includes lipoma, vascular neoplasms, hematopoietic tumors, and even meningioma. Of malignant peripheral nerve neoplasms, the vast majority are primary peripheral nerve sheath tumors. Malignancies of mesenchymal type are much less common. To date, only 12 cases of synovial sarcoma of nerve have been described. Whereas in the past, parallels were drawn between synovial sarcoma and malignant glandular schwannoma, an uncommon form of malignant peripheral nerve sheath tumor, molecular genetics have since clarified the distinction. Herein, we report 10 additional examples of molecularly confirmed synovial sarcoma, all arising within minor or major nerves. Affecting 7 female and 3 male patients, 4 tumors occurred in pediatric patients. Clinically and radiologically, most lesions were initially thought to be benign nerve sheath tumors. On reinterpretation of imaging, they were considered indeterminate in nature with some features suspicious for malignancy. Synovial sarcoma of nerve, albeit rare, seems to behave in a manner similar to its more common, soft tissue counterpart. Those affecting nerve have a variable prognosis. Definitive recommendations regarding surgery and adjuvant therapies await additional reports and long-term follow-up. The literature is reviewed and a meta-analysis is performed with respect to clinicopathologic features versus outcome.
authors.affiliation: Department of Pathology and Laboratory Medicine, Mayo Clinic, Rochester, MN 55905, USA. scheithauer.bernd@mayo.edu
authors.forename: Bernd W
authors.initials: BW
authors.lastname: Scheithauer
authors.forename: Kimberly K
authors.initials: KK
authors.lastname: Amrami
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Folpe
authors.forename: Ana I
authors.initials: AI
authors.lastname: Silva
authors.forename: Mark A
authors.initials: MA
authors.lastname: Edgar
authors.forename: James M
authors.initials: JM
authors.lastname: Woodruff
authors.forename: Allan D
authors.initials: AD
authors.lastname: Levi
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Spinner
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D018317:Nerve Sheath Neoplasms / Q000473:pathology; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D010524:Peripheral Nervous System Neoplasms / Q000235:genetics / Q000473:pathology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013584:Sarcoma, Synovial / Q000235:genetics / Q000473:pathology*; D055815:Young Adult
chemical_list: D015514:Oncogene Proteins, Fusion; C116512:SYT-SSX fusion protein