Multiple endocrine neoplasia

Last updated: June 14, 2023

Summarytoggle arrow icon

Multiple endocrine neoplasia (MEN) is a term used to describe three autosomal dominant syndromes that are associated with certain hormone-producing neoplasias. There are three subtypes: MEN 1, MEN 2A, and MEN 2B. MEN 1 is caused by an altered menin protein expression and presents with primary hyperparathyroidism, often in association with endocrine pancreatic tumors and/or pituitary adenomas. MEN 2A and MEN 2B are caused by a mutated RET proto-oncogene and both present with medullary thyroid carcinoma and sometimes pheochromocytoma. MEN 2A is further associated with primary hyperparathyroidism as well, while MEN 2B causes a marfanoid habitus and sometimes neurinomas. If any of the individual conditions associated with MEN are suspected, especially in patients with a positive family history, it is important to consider a diagnostic workup for any of the other associations. Specific diagnostic and management approaches can be found within the articles for each of the individual conditions. Family members of MEN patients should receive genetic counseling. Those positive for mutated genes should be closely monitored and should undergo a total thyroidectomy if positive for the RET proto-oncogene.

Overviewtoggle arrow icon

Overview of multiple endocrine neoplasia
Feature MEN 1 (formerly known as Wermer syndrome) MEN 2
MEN 2A (formerly known as Sipple syndrome) MEN 2B
  • Mutation of the MEN1 gene (located on chromosome 11) → altered expression of menin protein
Prinicipal manifestations
Further manifestations
  • Multiple neurinomas: mucosal neuromas (e.g., lips, tongue), intestinal ganglioneuromatosis ) [3]
  • Marfanoid habitus


MEN 1: 3 "P"s = Parathyroid, Pancreas, Pituitary gland

MEN 2A: 1 "M", 2 "P”s = Medullary thyroid carcinoma, Pheochromocytoma, Parathyroid

MEN 2B: 2 “M”s, 1 “P” = Medullary thyroid carcinoma, Marfanoid habitus/Multiple neuromas, Pheochromocytoma

Remembering that the inheritance pattern of MEN syndromes is autosomal dominant requires MENtal dominance.


Referencestoggle arrow icon

  1. Pheochromocytomas in Multiple Endocrine Neoplasia Type 2. Updated: January 1, 2015. Accessed: December 23, 2016.
  2. Alevizaki M, Saltiki K. Primary Hyperparathyroidism in MEN2 Syndromes. Recent Results Cancer Res. 2015; 204: p.179-186.doi: 10.1007/978-3-319-22542-5_8 . | Open in Read by QxMD
  3. Editors: Warrell DA, Cox TM, Firth JD; Contributor: Benz, Jr EJ. Oxford Textbook of Medicine. Oxford University Press ; 2003
  4. Kasper DL, Fauci AS, Hauser SL, Longo DL, Lameson JL, Loscalzo J. Harrison's Principles of Internal Medicine. McGraw-Hill Education ; 2015
  5. Williams L. Wermer Syndrome (MEN Type 1). In: Griffing GT, Wermer Syndrome (MEN Type 1). New York, NY: WebMD. Updated: February 18, 2015. Accessed: December 23, 2016.
  6. Arnold A. Multiple endocrine neoplasia type 1: Clinical manifestations and diagnosis. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. Last updated: May 28, 2015. Accessed: December 22, 2016.
  7. Author: Melanie L Richards. Type 2 Multiple Endocrine Neoplasia. In: Griffing GT, Type 2 Multiple Endocrine Neoplasia. New York, NY: WebMD. Updated: December 11, 2015. Accessed: December 22, 2016.

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