title: Radiation-associated synovial sarcoma: clinicopathologic and molecular analysis of two cases.
abstract: Development of a soft-tissue sarcoma is an infrequent but well-known long-term complication of radiotherapy. Malignant fibrous histiocytomas, extraskeletal osteosarcomas, fibrosarcomas, malignant peripheral nerve sheath tumors, and angiosarcomas are most frequently encountered. Radiation-associated synovial sarcomas are exceptional. We report the clinicopathologic, immunohistochemical, and molecular features of two radiation-associated synovial sarcomas. One tumor developed in a 42-year-old female 17 years after external irradiation was given for breast carcinoma; the other occurred in a 34-year-old female who was irradiated at the age of 7 years for a nonneoplastic condition of the left hand. Both lesions showed morphologic features of monophasic spindle cell synovial sarcoma, were immunoreactive for cytokeratins, epithelial membrane antigen, CD99, CD117 (c-kit), and bcl-2 and bore the t(X;18) (SYT-SSX1) translocation. We conclude that synovial sarcoma has to be added to the list of radiation-associated soft-tissue sarcomas.
authors.affiliation: University Institute of Pathology, Lausanne, Switzerland.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Egger
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Coindre
authors.forename: Jean
authors.initials: J
authors.lastname: Benhattar
authors.forename: Philippe
authors.initials: P
authors.lastname: Coucke
authors.forename: Louis
authors.initials: L
authors.lastname: Guillou
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000556:secondary; D009363:Neoplasm Proteins / Q000235:genetics; D009381:Neoplasms, Radiation-Induced / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D016609:Neoplasms, Second Primary / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D012097:Repressor Proteins / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013584:Sarcoma, Synovial / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D012983:Soft Tissue Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D014178:Translocation, Genetic
chemical_list: D009363:Neoplasm Proteins; D012097:Repressor Proteins; C093962:synovial sarcoma X breakpoint proteins