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 1: Multiple Endocrine Neoplasia (MEN) Syndromes: Conditions Associated With MEN Syndromes).

Table 1
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Conditions Associated With MEN Syndromes Condition MEN 1 MEN 2A MEN 2B Hyperparathyroidism ≥ 95% 10–20% — Enteropancreatic tumors 30–80% — — Pituitary adenomas 15–42% — — Medullary thyroid carcinoma — > 95% > 95% Pheochromocytomas — 40–50% 50% Mucosal neuromas — — ≈ 100% Marfanoid habitus — — ≈ 100% MEN = multiple endocrine neoplasia.

Last full review/revision September 2012 by Patricia A. Daly, MD; Lewis Landsberg, MD

Content last modified November 2012