Multiple neuroendocrine tumors (NET) of the pancreas often have a hereditary background. Sporadic and hereditary NET do not differ morphologically or with regard to their hormone expression. The most important clues for a hereditary background are provided by examination of the peritumoral pancreatic tissue, especially the morphology and hormone expression of the endocrine islets. Hyperplastic or dysplastic islets and microtumors with aberrant distribution of insulin and glucagon are the main features of hereditary NET. Morphological diagnosis of potentially hereditary NET has a relevant impact on the prognosis and clinical care of patients.