MEN syndromes

MEN (multiple endocrine neoplasia) is a group of autosomal dominant syndromes characterized by multiple endocrine tumors due to defective tumor suppressor genes

MEN 1 (Wermer's synd): 3 Ps (parathyroid, pancreas, and pituitary).

• • Hyperparathyroidism: 95%

  • Pancreatic tumors: insulinoma, gastrinomas (associated with Zollinger-Ellison synd), glucagonomas, VIPomas, or nonfunctioning tumors, 30 - 80%.

  • Pituitary tumors: 20 - 25%

  • Carcinoid, adrenal tumors, subcutaneous lipomas.

  • Genetics: MENIN gene

  • Screen if there is positive FH. Sr. Ca, PTH, gastrin, and prolactin

MEN 2A (Sipple's synd): Screen if there is positive FH of MEN 2 or in any Pt with medullary thyroid cancer or bilateral pheochromocytoma. Screen with RET proto-oncogene. If a RET proto-oncogene mutation is found, obtain basal stimulated calcitonin, plasma or urine metanephrines, Sr. PTH/calcium, gastrin.

• • Medullary thyroid cancer: 80 - 90%

  • Pheochromocytoma: 40%

  • Hyperparathyroidism: 25%

  • Genetics: RET proto-oncogene

MEN 2B: rare.

• • Medullary thyroid cancer: 100%

  • Mucosal neuromas: 100%

  • Pheochromocytomas: 50%

  • Ganglioneuromas of bowel: >40%

  • Marfanoid habitus: 75%

  • Genetics: RET proto-oncogene