[Successful resection of an advanced gastrointestinal stromal tumor by neoadjuvant chemotherapy with imatinib- a case report].

We report a case of a large gastric gastrointestinal stromal tumor (GIST), which we were able to curatively resect after treatment with a daily dosage of 400 mg imatinib for 3 months. The patient was a 46-year-old man whose chief complaint was anemia. Historical diagnosis by endoscopic biopsy was a c-kit-positive GIST of the stomach. From a CT scan, it was suspected that the tumor had directly invaded the pancreas. The tumor was 9 cm in size. For this case, total gastrectomy with distal pancreato splenectomy was necessary for curative resection. Imatinib mesilate was administered as neoadjuvant therapy according to the NCCN guidelines. After 3 months of treatment, CT revealed a dramatic reduction in tumor diameter of 61% and showed direct invasion of the pancreas. The radical operation was considered feasible and a partial gastrectomy was performed. The tumor did not invade other organs, and radical surgery was possible without rupture. The patient was recurrence free at his 12-month follow-up examination.