Association for
Multiple Endocrine
Neoplasia Disorders

What is MEN2 (formerly MEN2a)?

There are three types of tumor that can occur in MEN2. These occur in the butterfly-shaped thyroid gland in the neck, the parathyroid glands that lie close to or within the thyroid, and in the adrenal glands that sit on top of each kidney. Although most of the tumors are benign (not cancer), the tumor in the thyroid gland is always cancerous (medullary thyroid cancer or MTC). Each type of tumor may occur alone and independently of MEN.

Blood and urine tests for hormone levels as well as scans of the neck and abdominal area are all used to check for tumors. If a tumor is found an operation may be needed to remove either just the tumor itself or the whole of the affected gland. This is necessary in early childhood in the case of medullary thyroid cancer.

Thyroid Cancer

The butterfly-shaped thyroid gland is found at the base of the throat in the front of the neck. Almost 10 out of 10 (100%) of MEN2a patients will develop medullary thyroid cancer (MTC) by the time they are aged 40. The thyroid cancer or the pre-cancerous hyperplasia, may be found using blood tests to measure levels of calcitonin. Treatment involves an operation to remove the thyroid gland and the nearby lymph nodes (total thyroidectomy).

After the operation lifelong medication called levothyroxine needs to be taken. If calcitonin is still detected after the operation, further operations and other therapies are used to control it. MTC is usually slow growing and may often be managed effectively in this way without symptoms for many years. Children identified as having MEN2 are offered a thyroidectomy before the age of 5. Parathyroid glands are sometimes unavoidably removed at the same time as the thyroid gland (see parathyroids).

Parathyroid Glands

These small glands lie just next to or are sometimes embedded within the butterfly-shaped thyroid gland in the neck. Less than 1 in 4 (25%) of MEN2a patients will develop a parathyroid tumor called an adenoma. These tumors release large amounts of parathyroid hormone (PTH) and so can be easily found using blood and urine tests. Some symptoms of an untreated parathyroid tumor include irritability, ulcers, kidney stones, pancreatitis, bone fractures, osteoporosis, tiredness, muscle or bone pain, indigestion, poor memory and constipation. However most patients will have very few of these symptoms particularly when diagnosed and treated early on.

At the moment, the recommended treatment for parathyroid tumors is a relatively small operation to remove all of the glands, and involves only a few days in hospital. Medicines to control parathyroid hormone is available where surgery is not possible. After parathyroid glands are removed, patients may have to take a Vitamin D capsule to help the body absorb calcium.

Adrenal Glands

The body’s two adrenal glands are normally each about the size of a whole walnut and sit just on top of the kidneys. A tumor of the inner part of the adrenal gland is called a phaeochromocytoma (fee-o-cromo-sy-toma) and is almost always benign (not cancerous) in MEN. Phaeochromocytomas may grow for many years without causing severe symptoms but can be activated by events such as childbirth or surgery. Symptoms are varied and may include all or some of the following: sudden migraine-like headaches, palpitations, breathlessness, excessive sweating, high (or rarely low) blood pressure (constant or off- and-on), trembling, tiredness, depression, anxiety, and nausea with or without vomiting.

These growths may be detected using blood and urine tests as well as several different types of scan. Treatment involves an operation to remove the gland and tumor. A period of medicine before surgery is necessary to control the unstable blood pressure. If both adrenal glands are removed, lifelong steroid replacement therapy is necessary.

Author: Jo Grey with the help of the AMEND Medical Advisory Team

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