title: [Immunohistochemical and ultrastructural heterogeneity of gastrointestinal stromal tumors].
abstract: OBJECTIVE
  Digestive stromal tumors are the most frequent undifferentiated mesenchymal tumors. The prognosis of these tumors is difficult to predict and the histogenesis is still subject to controversy. However, the frequent and specific expression of CD117 (c-kit) by these tumors could suggest an origin from interstitial cells of Cajal. The aim of this study was to analyse the histological and immunohistochemical characteristics of 46 digestive stromal tumors surgically resected, with comparaison of CD34 and CD117 expression in these tumors. Sixteen tumors were analyzed on electron microscopy.
  
  
  RESULTS
  Sixty three and 74% of the stromal tumors were positive for CD117 and CD34 respectively. While CD117 expression was similar in all locations, on the contrary, there was a decreasing gradient of CD34 expression between gastric (87%) and jejunal (33%) tumors. All tumors with skeinoid fibers expressed CD117. Focal expression of smooth muscle actin was noted in 43% of the cases. The ultrastructural study showed no correlation with the immunohistochemical results.
  
  
  CONCLUSIONS
  Digestive stromal tumors show an immunophenotypic and ultrastructural heterogeneity. CD117 expression is frequent, but not constant.
authors.affiliation: Service d'Anatomie et de Cytologie Pathologiques, Hôpital Beaujon, Clichy.
authors.forename: A
authors.initials: A
authors.lastname: Handra-Luca
authors.forename: P
authors.initials: P
authors.lastname: Nahon
authors.forename: J F
authors.initials: JF
authors.lastname: Fléjou
authors.forename: G
authors.initials: G
authors.lastname: Molas
authors.forename: S
authors.initials: S
authors.lastname: Dubois
authors.forename: A
authors.initials: A
authors.lastname: Sauvanet
authors.forename: J
authors.initials: J
authors.lastname: Belghiti
authors.forename: P
authors.initials: P
authors.lastname: Ruszniewski
authors.forename: C
authors.initials: C
authors.lastname: Degott
authors.forename: B
authors.initials: B
authors.lastname: Terris
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018952:Antigens, CD34 / Q000032:analysis* / Q000276:immunology*; D020541:Coiled Bodies / Q000276:immunology; D004379:Duodenal Neoplasms / Q000276:immunology* / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D005743:Gastrectomy; D015972:Gene Expression Regulation, Neoplastic / Q000276:immunology*; D006801:Humans; D007150:Immunohistochemistry; D016130:Immunophenotyping; D007580:Jejunal Neoplasms / Q000276:immunology* / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D008297:Male; D008637:Mesenchymoma / Q000276:immunology* / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D008854:Microscopy, Electron; D008875:Middle Aged; D016577:Pancreaticoduodenectomy; D011237:Predictive Value of Tests; D011379:Prognosis; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis* / Q000276:immunology*; D018235:Smooth Muscle Tumor / Q000276:immunology* / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D013274:Stomach Neoplasms / Q000276:immunology* / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D016019:Survival Analysis
chemical_list: D018952:Antigens, CD34; D019009:Proto-Oncogene Proteins c-kit