GISTs associated with NF1 have no c-kit or PDGFRA gene mutations; however, c-Kit and PDGFRA expression are observed via immunohistochemical staining, suggesting that GIST can develop due to increased signal transduction through the MAP-kinase pathway owing to the somatic mutation of wild-type NF1 allele in tumors, without c-kit or PDGFRA gene mutations.[4,8,23,24] No c-kit or PDGFRA gene mutations were found; however, strong expression of c-Kit was observed in the present case based on immunohistochemical staining. This evidence concerns the gene KIT and gastrointestinal stromal tumor.