Imatinib was efficient in GISTs with p.K642E mutation with a disease control rate superior to 90% whatever the sporadic or inherited origin of the tumour.
We present a case in which a germline KIT exon 13 mutation (K642E) was discovered in a patient with multiple GISTs of rectum, small intestine, and esophagus, as well as diffuse hyperplasia of the interstitial cells of Cajal.