PKC Theta, A Novel Immunohistochemical Market For Gastrointestinal Stromal Tumors(GIST), Especially Useful For Identifying KIT-negative Tumors

PurposeTo investigate the expression and significance of PKC(?) in gastrointestinal stromal tumors(GIST).MethodsThe expression of PKC(?), CD 117, CD34, a-SMA and S-100 was detected by immunohistochemical method in 86 cases of GIST and 42 cases of gastrointestinal leiomyoma.ResultsAmong the 86 patients of GIST, the positive rates of PKC(?), CD 117, CD34, a-SMA and S-100 were 88.37%,82.56%,77.91%,32.56%,5.81%respectively. There were 12 PKC(?) positive expression of GIST in 15 CD117 negative expression cases. Among the 42 patients of gastrointestinal leiomyom, the positive rates of PKC(?), CD117, CD34, a-SMA and S-100 were 0%,0%,0%,100%,0%.ConclusionsPKC(?) is an immunohistochemical marker for GIST. PKC(?) is more sensitive and specific than CD117 to GIST, especially for CD117 negative GIST, or epithelioid GISTs with PDGFRA mutation. It suggests that to investigate PKC(?) and CD117 at same time will improve the rate of diagnosis of GIST.