The clinicopathologic and immunohistochemical features of gastrointestinal stromal tumors

Objective To investigate the clinicopathologic and immunohistochemical features of gastrointestinal stromal tumors(GISTs) and the expression of CD117,CD34,SMA,S-100.Methods The clinicopathologic features were studied,and the expression of CD117,CD34,SMA,S-100 and Vimentin were detected with immunohistochemical SP staining in 84 cases of GIST.Results The rate of the lowest risk tumor was 21.4%,and the low risk tumor was 31.0%.The rate of the midrange risk tumor and high risk tumor were 17.9% and 29.8% respectively.The positive rates of CD117 and CD34 were 94% and 86.9%,the positive rates of SMA and S-100 were 13.1% and 7.14%.Conclusion The gastrointestinal stromal tumors(GISTs) in stomach is always the lowest risk tumor and the low risk tumor.The GISTs in small intestine and large intestine are always the midrange risk tumor and the high risk tumor.The expression of CD117,CD34 and Vimentin are difffused.The combination of CD117 and CD34 immunohistochemical staining is necessary for the diagnosis of GIST.However,the immunophenotype is not a predictor for the degree of malignancy.