multiple endocrine neoplasia (MEN)
Most endocrine tumors strike one gland in one person by chance. Multiple endocrine neoplasia is different: it is a set of inherited conditions in which a single faulty gene predisposes many endocrine glands to grow tumors, often in the same family across generations. It is as if one typo in the body's blueprint leaves several glands prone to overgrow.
The syndromes are grouped by which glands they hit. MEN type 1 typically combines tumors of the parathyroids, the pancreatic islets, and the pituitary. MEN type 2 centers on medullary thyroid cancer, often together with pheochromocytoma and parathyroid disease. Each pattern traces to a specific gene — MEN1 for type 1 and the RET gene for type 2 — and the genes are passed on in a dominant fashion, so a child of an affected parent has a sizable chance of inheriting the risk.
Recognizing MEN changes care dramatically. Because the risk is genetic and lifelong, relatives can be tested for the mutation and screened for tumors before symptoms appear; in MEN type 2, a high-risk gene result can justify removing the thyroid early to prevent a cancer that would otherwise be near-certain. The goal shifts from treating one tumor to managing a lifelong, family-wide predisposition.
A young woman with kidney stones (from parathyroid overactivity), recurrent stomach ulcers (from a gastrin-secreting pancreatic tumor), and a relative who had a pituitary tumor fits the MEN type 1 pattern, prompting genetic testing of the whole family.
A family pattern, not just a single tumor.
A useful mnemonic for MEN type 1 is the three Ps: parathyroid, pancreas, and pituitary. MEN type 2 is dominated by medullary thyroid carcinoma, which arises from the calcitonin-producing C cells of the thyroid.