title: Histopathological features and clinical course of the gastrointestinal stromal tumors.
abstract: OBJECTIVE
  C-kit expression is a sensitive marker for a specific group of mesenchymal tumors of the gastrointestinal tract, gastrointestinal stromal tumors, the histogenesis and prognosis of which are uncertain.
  
  
  METHODS
  We have investigated the expression of c-kit by immunohistochemical analysis (APAAP method) in 12 out of 13 cases of mesenchymal gastrointestinal neoplasms operated from January 1991 to December 1998, in which the follow-up data were fully available. Furthermore, the c-kit expression was correlated both with the expression of vimentin, CD34 and the mitotic rate, and with the expression of muscle (muscle-specific actin-HHF35 and desmin) or neural (neuron-specific enolase) differentiation markers.
  
  
  RESULTS
  C-kit was expressed in all 12 cases (100%). Two different patterns of expression were observed: cytoplasmic in 7 (58.3%) cases and nuclear in 3 (25%) cases; in 2 (16.7%) cases both cytoplasmic and nuclear immunostaining was detected. Three (60%) out of the five cases showing a nuclear c-kit expression were also neuron-specific enolase positive, whereas none of the cases showing an exclusively cytoplasmic c-kit expression was neuron-specific enolase positive. The correlation between the two patterns of c-kit expression and the follow-up data have shown a trend towards a better prognosis in gastrointestinal stromal tumors with a nuclear c-kit immunostaining and neuron-specific enolase positivity, but the relatively low number of cases does not allow us to draw conclusions. In gastrointestinal stromal tumors the mitotic rate (> 2 x 10 HPF vs. < 2 x 10 HPF) is related with statistically significant differences (P < 0.05) to the 5-year survival (0% vs. 80%, respectively).
  
  
  CONCLUSIONS
  These findings, together with the already known c-kit nuclear immunostaining in normal adrenal medullary cells, suggest that a nuclear c-kit expression in gastrointestinal stromal tumors is consistent with a neural differentiation. In this study the mitotic rate has demonstrated a significant influence on the prognosis of gastrointestinal stromal tumors.
authors.affiliation: Third Department of General Surgery, University La Sapienza, Rome, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Di Matteo
authors.forename: Edoardo
authors.initials: E
authors.lastname: Pescarmona
authors.forename: Nadia
authors.initials: N
authors.lastname: Peparini
authors.forename: Filippo Maria
authors.initials: FM
authors.lastname: Di Matteo
authors.forename: Kenneth Paul
authors.initials: KP
authors.lastname: Zeri
authors.forename: Domenico
authors.initials: D
authors.lastname: Mascagni
authors.forename: Rita
authors.initials: R
authors.lastname: Mele
authors.forename: Alessandro
authors.initials: A
authors.lastname: Maturo
authors.forename: Adriano
authors.initials: A
authors.lastname: Redler
authors.forename: Enrico
authors.initials: E
authors.lastname: De Antoni
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D004064:Digestive System / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D005770:Gastrointestinal Neoplasms / Q000401:mortality / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008940:Mitotic Index; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology; D009379:Neoplasms, Muscle Tissue / Q000401:mortality / Q000473:pathology*; D011379:Prognosis; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis*; D017154:Stromal Cells / Q000473:pathology; D015996:Survival Rate
chemical_list: D014408:Biomarkers, Tumor; D019009:Proto-Oncogene Proteins c-kit