Multiple Endocrine Neoplasia, Type 1 (MEN 1) (Multiple Endocrine Adenomatosis, Type I; Wermer Syndrome) By Lawrence S Kirschner, MD, PhD, The Ohio State University; Pamela Brock, MS, CGC, The Ohio State University Reviewed / Revised Jun 2023 View Patient Education Symptoms and Signs Diagnosis Treatment Key Points Multiple endocrine neoplasia, type 1 (MEN 1) is an autosomal dominant syndrome characterized by hyperplasia or adenomas of the parathyroid glands, pancreatic islet cell tumors (also known as pancreatic neuroendocrine tumors), and / or pituitary gland tumors.