[A case of multiple liver metastases after resection of gastrointestinal stromal tumor of the small intestine that was successfully treated with imatinib mesylate].

A 73-year-old man was found to have an intestinal tumor, approximately 10 cm in diameter, on computed tomography (CT). In September 2001, he underwent partial resection of the jejunum with partial colectomy and left nephrectomy. Pathological examination showed 2 mitoses per 50 high-power fields, and immunohistochemical analysis showed positive staining for c-kit. Based on the above findings, the tumor was diagnosed as a high-risk malignant gastrointestinal stromal tumor( GIST) of the small intestine; the patient was followed up and no adjuvant therapy was administered. In October 2005, an abdominal CT scan revealed 2 tumors with diameters of 21 and 28 mm in the S8 and S7 region of the liver, respectively, and the patient was diagnosed with liver metastases from GIST. After obtaining adequate informed consent, chemotherapy with imatinib (400 mg/day) was initiated. Although the patient experienced partial response (PR) 2 months after the treatment, grade 3 neutropenia and general fatigue were observed. Therefore, the treatment schedule was changed to 1 week of therapy, followed by 1 week of rest. At present, at 91 months after the diagnosis of liver metastases, the patient shows no signs of recurrence. Therefore, it is important that adjuvant chemotherapy should be considered for the treatment of patients with high-risk malignant GIST.