Clinicopathological and immunohistochemical studies in 36 cases of gastrointestinal stromal tumor

Objective To investigate the pathological and immunohistochemical features of gastrointestinal stromal tumor (GIST). Methods Thirty-six cases of GIST were studied by histopathology and immunohistochemistry.The expressions of CD34, CD117,vimentin, SMA, NSE and S-100 protein were detected with S-P immunohistochemical method. Results The neoplastic cells of GIST were mainly spindle, epithelioid, or both, which arranged in bunch, fence, vortex or nest. Among 36 cases, 12 were benign, 10 malignant and 14 borderline lesions. The positive rats of CD117 and CD114 were 94.4% and 80.5%,respectively.The expression of vimetin ,SMA and S-100 in GIST was positive when neoplastic cells differentiated towards smooth muscle or nerve. Conclusions The neoplastic cells of GIST are spindle or epitheloid. Histostructures vary a lot, but immunophenotypes are all the same. CD117 and CD34 may be taken as the markers in the diagnosis and differential diagnosis of GIST.