[A case of gastrointestinal stromal tumor of the stomach which rapidly increased in size over the period of three years].

The patient was a 75-year-old woman. Esophagogastroduodenoscopy revealed a submucosal tumor 2 cm in size on the anterior wall of the cardiac part of the stomach. Three years later, she visited at our hospital with the chief complaints of tarry stool and dizziness. Proximal gastrectomy was performed, because endoscopically the tumor increased to 7cm in size with ulceration and it was considered to be malignant. Pathological examination was high-risk gastrointestinal stromal tumor. In this case, the submucosal tumor increased by 3.5 times. GIST is needed to be observed carefully and be treated in the appropriate time.