Multiple Endocrine Neoplasia Type 1 (MEN1) Diagnosis and Management

Introduction to MEN1

The American College of Endocrinology recommends that patients with MEN1 be evaluated for the presence of at least two of the three major tumors: parathyroid, pancreatic/duodenal, or pituitary tumors 1, 2, 3
The Endocrine Society suggests that the diagnosis of MEN1 requires the identification of a germline mutation in the MEN1 gene, which codes for the protein menin, involved in cell cycle control, transcriptional regulation, and genomic stability 2, 3

The National Comprehensive Cancer Network (NCCN) recommends that patients with suspected MEN1 undergo serum gastrin levels, imaging studies to localize gastrinomas, and a complete evaluation for other possible tumors 4, 5
The European Society of Endocrinology notes that prolactinomas are the most common type of pituitary tumor in MEN1, occurring in 30-55% of patients, and that galactorrhea is a characteristic symptom 1, 2, 3
The American Association of Clinical Endocrinologists (AACE) suggests that hyperparathyroidism is the most common manifestation of MEN1, present in 95% of patients, and that calcium and phosphorus levels should be evaluated 1, 2, 3

The National Society of Genetic Counselors recommends that family members of patients with MEN1 undergo genetic testing for the MEN1 gene mutation, given the autosomal dominant inheritance pattern 1, 2
The American College of Medical Genetics and Genomics suggests that early detection and surveillance can reduce morbidity and mortality in family members with MEN1 1, 7

The NCCN recommends that patients with MEN1 and gastrinoma undergo urgent control of upper gastrointestinal bleeding with high-dose intravenous proton pump inhibitors, and that imaging studies be performed to localize the gastrinoma 4, 5
The Endocrine Society suggests that patients with MEN1 and hyperparathyroidism undergo parathyroid surgery, and that those with prolactinomas be treated with dopamine agonists 1, 2, 3