Merck Manual

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Overview of Multiple Endocrine Neoplasias (MEN)

(Familial Endocrine Adenomatosis; Multiple Endocrine Adenomatosis)


Patricia A. Daly

, MD, University of Virginia;

Lewis Landsberg

, MD, Northwestern University Feinberg School of Medicine

Last review/revision Apr 2021 | Modified Sep 2022
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The multiple endocrine neoplasia (MEN) syndromes comprise 3 genetically distinct familial diseases involving adenomatous hyperplasia and malignant tumors in several endocrine glands.

Clinical features depend on the glandular elements involved.


Each syndrome is inherited as an autosomal dominant trait with a high degree of penetrance, variable expressivity, and production of seemingly unrelated effects by a single mutant gene. The specific mutation is not always known.

Symptoms and signs develop at any age. Proper management includes early identification of affected individuals within a kindred and surgical removal of the tumors when possible. Although these syndromes are genetically and clinically distinct, significant overlap exists (see table Conditions Associated With MEN Syndromes Conditions Associated With Multiple Endocrine Neoplasia Syndromes Conditions Associated With Multiple Endocrine Neoplasia Syndromes ).

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