[A case of recurrent GIST successfully treated with low-dose imatinib mesilate].

A 75-year-old man underwent partial resection of the small intestine for GIST in January 2000. A recurrent tumor revealed in the intra pelvic space was removed by two operations, and imatinib (400 mg/day) was given after the third operation. As successive administration was not able to be continued due to side effects such as anorexia and fatigue, the recurrent tumor enlarged. After imatinib was given at 200 mg/day, the defecation trouble was improved and the tumor decreased partially on CT image. His partial response has continued over one year. Mutation analysis revealed deletion and point mutation in exon 11 of c-kit gene. Low-dose imatinib administration should be considered in case of side effects at the standard dose.