NF1 and gastrointestinal stromal tumor: The SDHBIHC+ subgroup includes cases of NF1-mutated GIST, that are commonly intestinal, multifocal and have an IGF1R negative staining, and also sporadic KITWT/PDGFRAWT GIST, arising in the adult from any part of gastrointestinal tract [15, 21, 25].