Our systematic review encompasses studies conducted over the past decade, focusing on the incidence, diagnosis, and treatment of PanNETs and/or LNETs encountered in hereditary syndromes such as Multiple Endocrine Neoplasia type 1 (MEN1), MEN4, von Hippel–Lindau (VHL), Tuberous Sclerosis Complex (TSC), and Neurofibromatosis type 1 (NF1). This evidence concerns the gene MEN1 and neurofibromatosis.