What is MEN?

Multiple Endocrine Neoplasia (MEN) disorders are inherited syndromes— this means they can be passed down in families. MEN disorders cause more than one gland of the endocrine (gland) system to develop neuroendocrine tumours, both benign (not cancer) and cancerous. The affected glands then over-produce hormones (the body’s chemical messengers), which in turn cause a variety of different symptoms. Each tumour may occur alone and independently of MEN. Early diagnosis and treatment are essential to help reduce the impact of these conditions on the patient.


MEN type 1

In MEN1, tumours may develop in the parathyroid glands in the neck, pituitary gland in the head and the pancreas in the abdomen.

MEN type 2

There are 3 distinct subtypes of MEN2:

MEN2A may present with tumours of the thyroid and parathyroid glands in the neck, and the adrenal glands near the kidneys;

MEN2B may present with tumours of the thyroid and adrenal glands, and throughout the gut. In addition, patients with MEN2B may have long fingers and toes and an unusual distinctive facial
appearance. MEN2B may also be referred to as MEN3.

FMTC (Familial MTC) presents only with hereditary cancer of the thyroid gland and is now considered a milder form of MEN2A.

Although most of the tumours in MEN2 are benign (not cancer), the thyroid tumours are always cancerous (medullary thyroid cancer), and can occur in early childhood. For this reason, surgery to remove the thyroid gland is usually necessary at an early age in children who have been identified as having MEN2. In addition, the adrenal tumours (pheochromocytomas) often produce too much adrenal gland hormones, which can raise blood pressure and lead to strokes and early death if left untreated.