[A Case of GIST of Stomach with Peritoneal Dissemination-Long-Term Survival with Imatinib and Surgical Resection].

A 63-year-old female patient underwent resection of a gastrointestinal stromal tumor(GIST)at the age of 48 years. After surgery, she had adjuvant chemotherapy. She had been recurrence-free for 10 years. Two years after completion of medical therapy, local peritoneal recurrence of GIST was observed, and medical therapy with imatinib was restarted. The response was good, but 1 year after resumption of medical therapy, progression was observed, and imatinib resistance was suspected, and recurrent tumor resection was performed. After the reoperation, the patient continued medical treatment with imatinib. Two years after the reoperation, a tumor suspected to be recurrent was found in the abdominal cavity. Tumor resection was performed. Histopathological examination revealed c-kit and CD34 positivity, leading to a diagnosis of recurrence of GIST. Imatinib is the mainstay of treatment in patients with recurrent GISTs, and sunitinib may be considered if the patient becomes resistant to imatinib, or surgical treatment may be considered if the lesion can be resected. In this study, we report a case of GIST with peritoneal dissemination in which imatinib therapy was continued after surgery, but the disease recurred twice. We investigate the prognostic value of continued imatinib therapy after surgical resection of locally recurrent GIST.