title: Epithelioid osteosarcoma of bone. Immunocytochemical evidence suggesting divergent epithelial and mesenchymal differentiation in a primary osseous neoplasm.
abstract: BACKGROUND
  The combination of a primary osteosarcoma of bone with a second carcinomatous cell type has been recognized, although immunohistochemical studies currently have not been performed in an attempt to understand the histogenesis of such a tumor.
  
  
  METHODS
  In this report, the authors performed immunohistochemical studies on a primary osseous carcinosarcoma. Using a biotin-streptavidin peroxidase conjugate technique, the expression of keratin, epithelial membrane antigen, and vimentin was analyzed.
  
  
  RESULTS
  The epithelial cells expressed cytokeratin and epithelial membrane antigen but did not express vimentin. The mesenchymal cells strongly expressed vimentin, and only rare cells expressed cytokeratin.
  
  
  CONCLUSIONS
  The clinical, morphologic, and immunophenotypic data in this instance strongly suggest divergent differentiation of a primitive multipotential uncommitted stem cell in a primary osseous tumor.
authors.affiliation: Strong Memorial Hospital, Rochester, New York.
authors.forename: K
authors.initials: K
authors.lastname: Kramer
authors.forename: D G
authors.initials: DG
authors.lastname: Hicks
authors.forename: J
authors.initials: J
authors.lastname: Palis
authors.forename: R N
authors.initials: RN
authors.lastname: Rosier
authors.forename: J
authors.initials: J
authors.lastname: Oppenheimer
authors.forename: M D
authors.initials: MD
authors.lastname: Fallon
authors.forename: H J
authors.initials: HJ
authors.lastname: Cohen
mesh_terms: D000293:Adolescent; D001859:Bone Neoplasms / Q000378:metabolism / Q000473:pathology*; D004848:Epithelium / Q000473:pathology; D006801:Humans; D007633:Keratins / Q000378:metabolism; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D018396:Mucin-1; D012516:Osteosarcoma / Q000378:metabolism / Q000473:pathology*; D014746:Vimentin / Q000378:metabolism
chemical_list: D008562:Membrane Glycoproteins; D018396:Mucin-1; D014746:Vimentin; D007633:Keratins