Multiple Endocrine Neoplasia (MEN) disorders are rare inherited syndromes which usually cause more than one gland in the body to form growths (neuroendocrine tumors or NETs). Most of the growths occurring in MEN patients are benign (not cancer), but some do develop into cancer. In MEN1, cancer may develop in certain cells in the pancreas. In MEN2, cancer almost always develops in the thyroid gland. Where possible, surgery to remove the thyroid in children diagnosed with MEN2a is performed before age of 5, or within the first year of life in MEN2b. Affected glands over-produce hormones (the body’s chemical messengers), causing a variety of different symptoms. There are currently three main types of MEN, MEN1, MEN2a and MEN2b (MEN3) with other even rarer variants identified. Each child of an affected parent has a 1 in 2 or 50% risk of inheriting the condition.