title: Biphasic synovial sarcoma in the small intestinal mesentery.
abstract: BACKGROUND
  A 46-year-old man presented with recurrent anemia and polyarthralgia. Investigations revealed a mass in the ileal mesentery, which was resected. Results of routine histologic examination suggested a diagnosis of synovial sarcoma, a rare malignancy usually not reported at this site.
  
  
  METHODS
  Tissue was examined immunohistochemically, ultrastructurally, and by fluorescent in situ hybridization to confirm the diagnosis.
  
  
  RESULTS
  Immunohistochemical studies revealed widespread labeling for cytokeratins and focal labeling for desmin and vimentin in the epithelial component, with labeling for epithelial membrane antigen in the epithelial and spindle-cell components. Fluorescent in situ hybridization analysis showed the characteristic t(X;18) translocation of synovial sarcoma.
  
  
  CONCLUSIONS
  This is a unique case of synovial sarcoma in the small intestinal mesentery. Immunohistochemical labeling confirmed the diagnosis, although, to the authors' knowledge, the pattern of desmin labeling has not been described previously. The clinical association with polyarthralgia, which resolved after removal of the neoplasm, also has not been described previously.
authors.affiliation: Department of Pathology, University of Liverpool, United Kingdom.
authors.forename: T R
authors.initials: TR
authors.lastname: Helliwell
authors.forename: A P
authors.initials: AP
authors.lastname: King
authors.forename: M
authors.initials: M
authors.lastname: Raraty
authors.forename: C
authors.initials: C
authors.lastname: Wittram
authors.forename: A I
authors.initials: AI
authors.lastname: Morris
authors.forename: S
authors.initials: S
authors.lastname: Myint
authors.forename: M J
authors.initials: MJ
authors.lastname: Hershman
mesh_terms: D003893:Desmin / Q000032:analysis; D006801:Humans; D007082:Ileum; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D007633:Keratins / Q000032:analysis; D008297:Male; D008643:Mesentery; D008875:Middle Aged; D010534:Peritoneal Neoplasms / Q000175:diagnosis* / Q000473:pathology; D013584:Sarcoma, Synovial / Q000175:diagnosis* / Q000473:pathology; D014746:Vimentin / Q000032:analysis
chemical_list: D003893:Desmin; D014746:Vimentin; D007633:Keratins