Roughly 75% of GIST cases present activating mutations in KIT gene.16, 25The available data suggest that GIST with KIT mutations have an incidence close to 8 cases per 106individuals per year in most regions, GIST with KIT mutations are most common in individuals >18 years of age.7, 9KIT mutations are also found in micro-GIST and mini-GIST, as well as in familial GIST resulting from germline mutations in these genes. This evidence concerns the gene KIT and gastrointestinal stromal tumor.