RESUMO
Multiple endocrine neoplasia type 1 (NEM1) is an uncommon autosomal dominant disease caused by an alteration of menin, a tumor suppression protein and is characterized by the presence of primary tumors in at least two different endocrine tissues. It is described as the three P diseasesince it involves mainly the pituitary, parathyroid and pancreas. However more than 20 different tumor locations have been described. Most tumors are benign and primary hyperparathyroidism is the first manifestation of the disease in 90 percent of cases enteropancreatic tumors appear in approximately 60 percent of patients and pituitary adenomas, usually prolactinomas, in 30 percent. Skin lesions, non functional adrenal adenomas and neuroendocrine tumors such as carcinoid are also part of the disease. We describe the pathogenesis, clinical presentation, diagnosis and treatment of NEM1.