OBJECTIVETo investigate the clinicopathological diagnosis and expressions of CD117, CD34, SMA, S-100 protein, Vimentin(Vim) and desmin in gastrointestinal stromal tumors (GISTs).

METHODSA retrospective analysis of the clinical data and the results of various examinations was conducted among 35 patients with pathologically confirmed GISTs undergoing surgical resection. The expressions of CD117, CD34, SMA, S-100, Vim and desmin in the tumor tissues were detected by immunohistochemistry with SP method.

RESULTSIn these GIST cases, the tumors were located mostly in the stomach (n=11), small intestines (n=11), and abdominal cavity (n=5). The main clinical manifestations included abdominal distension, abdominal pain, gastrointestinal bleeding, and abdominal masses. The positivity rates of CD117 and CD34 in the tumors were 94.3% and 91.4%, respectively, both significantly higher than those of SMA, S-100, Vim and Desmin (P<0.001), and also higher than that in leiomyoma (P<0.0001). The positivity rate of Desmin was only 2.9% in the tumors, significantly lower than those of CD117 and CD34 (P<0.05) and that in liomyoma (P<0.001).

CONCLUSIONSGISTs occur mostly in the stomach and small intestines, and endoscopy, ultrasound endoscope and CT examination are effective modalities for diagnosis of GISTs. A definite diagnosis of GISTs can be established in the presence of positive expression of CD117 and CD34 and negative expression of Desmin in the tumor.