multiple endocrine neoplasia type 1

Multiple Endocrine Neoplasia (MEN) is a group of rare, inherited disorders that cause tumors to develop in multiple glands of the endocrine system. These conditions are passed down in an autosomal dominant pattern, meaning there's a 50% chance of passing the condition to a child.1

MEN type 1 (MEN1) primarily affects the parathyroid glands, pancreatic islets of Langerhans, and the pituitary gland. The most common issue in MEN1 is primary hyperparathyroidism, occurring in about 90% of patients. Other associated conditions include pancreatic islet-cell tumors and pituitary adenomas.1

MEN type 2 (MEN2) involves medullary carcinoma of the thyroid gland, pheochromocytomas (tumors of the adrenal glands), and sometimes hyperparathyroidism. MEN2B also includes specific physical characteristics and ganglioneuromas.1

The underlying cause for both MEN1 and MEN2 are mutations in specific genes: MEN1 for MEN1 and the RET proto-oncogene for MEN2. Genetic testing is crucial for diagnosis and for identifying at-risk family members, allowing for early monitoring and treatment.12