Abstract:Objective:To study the clinical manifestations, diagnosis ,treatment and prognosis of gastrointestinal stromal tumors(GISTs). Methods:Clinical and pathological data of 31 cases of GISTs admitted from 1995 to 2005 were retrospectively studied. Results:Using Fletcher′s classification ,tumors were divided in very low risk(3/31,9.68%), low risk (5/31,16.13%), intermediate risk (15/31,48.39%), and high risk (8/31,25.81%).The positive expression rate of CD117,CD34,desmin,SMA and S-100 protein was 94%, 87%, 39%,35% 26%,respectively. There was no significant difference in the expression of CD117,CD34,desnin, SMA and S-100 protein among all the different risk groups (χ2=0.35,0.12,0.03,0.05,0.01,P>0.05).The infiltration of tumor to the muscularis mucosa or serosa layers was significantly correlated with the risk of GISTs(χ2=4.87,P<0.05).Conclusions:Fletcher′s classification is scientific and rational for assessment of the stage of GISTs. Recurrence rate of intermediate risk and high risk cases was 26.0% which was much higher than that of very low risk and low risk case(P<0.001). Complete surgical excision of the GISTs is the best choice for cure. The infiltration of tumor to the muscularis mucosa or serosa layers is an important indicator of the risk of GISTs. Mitotic rate is an independent factor that may predict the prognosis of GISTs.