title: Uncommon pattern in soft tissues epithelioid sarcoma.
abstract: Epithelioid sarcoma (ES) is a rare tumor, but extremely versatile, simulating easily both clinically and morphologically multiple benign lesions as granulomas and malignant tumors as achromic melanomas or carcinomas. Especially the histological aspects are suggesting for an epithelial tumor. The atypical biological behavior of tumor is conferred by: a propensity for lymph nodes metastases, large dimensions of tumor, unusual localizations.
  
  
  OBJECTIVE
  To report some peculiar histological and immunophenotypic aspects in soft parts epithelioid sarcoma.
  
  
  METHODS
  We analyzed retrospectively three cases of epithelioid sarcomas with unusual clinico-morphological (large dimensions), histopathological (absence of necrosis) and immunohistochemical (IHC) patterns selected from 200 consecutive soft parts malignant tumors of "Victor Babeş" National Institute Bucharest files. For the immunohistochemical (IHC) staining, the following antibodies were used: vimentin, EMA, cytokeratins (KL1, CK19), S-100 protein, CD68, p53 protein, vascular markers (CD31, CD34, FVIII-related antigen), HMB45, MELAN A.
  
  
  RESULTS
  The tumors had unusually large dimensions, the absence of necrosis, a vaguely alveolar pattern; the IHC staining showed a strong positivity of S-100 protein, a variable expression of cytokeratins KL1 and CK19, in association to a scarce positivity for EMA, zonal positivity for CD34 and diffuse reaction for vimentin.
  
  
  CONCLUSIONS
  The immunophenotype of ES may have a large variability and the correlation to clinico-morphological aspects is necessary for a good diagnostic assessment.
authors.affiliation: Immunohistochemistry Department, "Victor Babeş" National Institute of Pathology, Bucharest. carmena@vbabes.ro
authors.forename: Carmen
authors.initials: C
authors.lastname: Ardeleanu
authors.forename: Maria
authors.initials: M
authors.lastname: Comănescu
authors.forename: Violeta
authors.initials: V
authors.lastname: Comănescu
authors.forename: F
authors.initials: F
authors.lastname: Andrei
mesh_terms: D000328:Adult; D015703:Antigens, CD / Q000032:analysis; D018952:Antigens, CD34 / Q000032:analysis; D002648:Child; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D012189:Retrospective Studies; D012509:Sarcoma / Q000473:pathology*; D012983:Soft Tissue Neoplasms / Q000473:pathology*
chemical_list: D015703:Antigens, CD; D018952:Antigens, CD34