Complete resection after imatinib treatment of a gastrointestinal stromal tumor of the ileum with peritoneal metastases: report of a case.

A 70-year-old woman with a pelvic tumor had undergone exploratory laparoscopy at another institution, which revealed many peritoneal nodules. Immunohistochemical staining of a biopsy specimen of the peritoneal nodules was positive for KIT. Thus, a gastrointestinal stromal tumor (GIST) was diagnosed and imatinib treatment was begun. After 16 months of this treatment, the tumor size had decreased from 51 x 55 mm to 22 x 17 mm, and surgery was performed. Laparotomy revealed complete regression of the peritoneal lesions. The primary tumor was seen to arise from the small intestine and to loosely adhere to the rectum. We performed partial resection of the small intestine. Imatinib therapy was restarted 1 month postoperatively, and the patient is doing well after 12 months of follow-up. We report this case to show that there is the possibility of curative salvage surgery after long-term imatinib treatment in some patients with peritoneal metastases of a GIST.