SST and gastrointestinal stromal tumor: Gastrointestinal tract neoplasms in NF-1 patients are more frequent than in the general population and occur in three main forms [6, 12, 17, 18]: hyperplasia of the submucosal and myenteric nerve plexuses and mucosal ganglioneuromatosis that leads to disordered gut motility; gastrointestinal stromal tumours (GIST) with varying degrees of neural or smooth muscle differentiation; distinctive glandular somatostatine-rich carcinoid in the periampullary region of the duodenum, which contains psammoma bodies and may be associated with pheochromocytoma.