A CASE OF GASTROINTESTINAL STROMAL TUMOR OF STOMACH WHICH IS IMMUNOHISTOCHEMICALLY POSITIVE FOR C-KIT

Abstract

A 75-year-old woman was admitted to our hospital because of epigastric pain. Upper endascopic examination revealed smooth submucosal tumor in the upper body of the stomach, which was 60mm in size and had bridging fcld by an upper gastrointestinal barium series. EUS revealed a low echoic mass with some microcystic areas, derived from the forth layer of the gastric walL We suspected of leiomyosarcoma of the stomach and laparotomy wasperformed. The tumor was diagnosed gastrointestinal stromal tumor (GIST) of the stomach and a few mitoses (3/25HPF) were observed on histological examination. Tumor cells were positive for CD34 and c-kit, but negative for actin and s-100 by histochemical examination. Recently it has been said that the c-kit recepter is an useful marker for stromal turnors that have a wide differential diagnosis in view of variable histological apperances. We report the case of GIST which was positive for c-kit and discuss the concept and the hisagenesis of GIST.