Gastrointestinal stromal tumours (GISTs) are rare tumours of mesenchymal origin, most likely arising from precursors of the interstitial cells of Cajal of the gastrointestinal tract.1 The estimated incidence of GIST is 12–15 cases per 1 million population in Western countries.2,3 Approximately 75–80% of GIST cases show activating mutations in KIT (CD117). This evidence concerns the gene KIT and gastrointestinal stromal tumor.