Multiple endocrine neoplasia type 2 (MEN2) is a hereditary condition associated with three primary types of tumors: medullary thyroid cancer, parathyroid tumors, and pheochromocytoma. MEN2 is classified into three subtypes based on clinical features.
MEN2A, which affects 60% to 90% of MEN2 families
Medullary thyroid cancer: 98% to 100% with MEN2A are affected
Pheochromocytoma, a typically benign (noncancerous) tumor of the adrenal glands: 50% with MEN2A affected
Parathyroid adenoma (benign tumor) or hyperplasia, meaning increased size, of the parathyroid gland: 5% to 10% with MEN2A affected
MEN2B, which affects 5% of MEN2 families
Medullary thyroid cancer: 98% to 100% with MEN2B affected
Pheochromocytoma: 50% with MEN2B affected
Mucosal neuromas, which is a benign tumor of nerve tissue on the tongue, lips and throughout the gastrointestinal tract: 95% to 98% affected
Digestive problems caused by disordered nerves in the gastrointestinal tract: 75% to 90% affected
Muscle, joint, and spinal problems: 95% affected
Typical facial features, including swollen lips and thick eyelids: 75% to 90% affected
Familial medullary thyroid cancer (FMTC), which affects 5% to 35% of MEN2 families
Medullary thyroid carcinoma only
Sources: Gagel RF, Marx SJ. “Multiple endocrine neoplasia.” Williams Textbook of Endocrinology, Chapter 40, 11th ed., Philadelphia, 2008, and Eng C, Clayton D, et al. Grubbs EG, Gagel RF. My, How Things Have Changed in Multiple Endocrine Neoplasia Type 2A! J Clin Endocrinol Metab 100(7):2532-5, 7/2015. PMID: 26151398.
What causes MEN2?
MEN2 is a genetic condition. This means that the cancer risk and other features of MEN2 can be passed from generation to generation in a family. The gene associated with MEN2 is called RET. A mutation (alteration) in the RET gene gives a person an increased risk of developing medullary thyroid cancer and other tumors associated with MEN2.