Gastrointestinal stromal tumor of the stomach.

We report a case of gastrointestinal stromal tumor (GIST) of the stomach. The patient was a 79-year-old woman with two gastric submucosal tumors detected by ultrasonography. Proximal gastrectomy was carried out and the tumors were diagnosed as GIST by histological and immunohistochemical investigations. Mesenchymal tumors of the gastrointestinal tract have been traditionally regarded as largely leiomyomatous lesions. However, GIST and other tumors have been distinguished recently on the basis of tumor cell differentiation shown by immunohistochemical studies. We discuss the concept and the immunohistochemical characteristics of GIST.