RESUMO
Objective To study the clinicopathological and immunophenotypical features of gastrointestinal stromal tumor (GIST). Methods A SP Immunohistochemical method was selected to detect the 71 cases of GIST for a panel of antibodies CD117, CD34, Vim, Act, S-100. Results The patient's ages ranged from 21 years to 86 years (mean 55 years) including 34 male and 37 female. Most cases were diagnosed by bellyache and alimentary tract bleeding. Tumor size varied from 0.3 cm to 23 cm (mean 5.8 cm). GIST were composed of spindle cells and (or) epithelioid cells. Various sized eosinophilic globules were observed between the tumor cells and were designated as skeinoid fibers. The positive rate by immunohistochemical methods for CD117 and CD34 were 94.4 % and 73.2 % respectively. Conclusion GIST predominantly occurred in middle aged or older patients over 40 years. The histological characters are similar to smooth muscle tumor and schwannoma. CD117 and CD34 are more specific and sensitive markers. GIST may have been derived from interstitial cell of cajal or show differentiation toward interstitial cell of Cajal.