• Also known as Wermer syndrome
• Characterized by tumors of the parathyroid, anterior pituitary, and pancreas
• Tumors may develop synchronously or metachronously, may be benign or malignant, and may be hyperplasia, adenomas, or carcinoma
• Pancreatic tumors include functioning and nonfunctioning islet tumors such as gastrinoma, insulinoma, glucagonoma, VIPoma, somatostatinoma, pancreatic polypeptide tumors (PPomas)
• Other tumors in MEN 1 can include adrenocortical tumors, thymic or bronchial carcinoid tumors, multiple lipomas, cutaneous angiofibromas and collagenomas
• Syndrome is transmitted as autosomal dominant trait
• Most common mutation is in the menin gene on 11q13
• Trait has 100% penetrance but variable expressivity