Multiple endocrine neoplasia (MEN) II

Endocrine glands

Endocrine glands release hormones (chemical messengers) into the bloodstream to be transported to various organs and tissues throughout the body. For instance, the pancreas secretes insulin, which allows the body to regulate levels of sugar in the blood. The thyroid gets instructions from the pituitary to secrete hormones which determine the pace of chemical activity in the body (the more hormone in the bloodstream, the faster the chemical activity; the less hormone, the slower the activity).

Also known as: Sipple syndrome and MEN II

Definition

Multiple endocrine neoplasia, type II (MEN II) is an inherited disorder in which one or more of the endocrine glands are overactive or form a tumor. Endocrine glands most commonly involved include:

  • Adrenal (about half the time)
  • Parathyroid (20% of the time)
  • Thyroid (almost all of the time)

See also: MEN I

Causes, incidence, and risk factors

The cause of MEN II is a defect in a gene called RET. This defect causes many tumors to appear in the same person, but not necessarily at the same time. The adrenal tumor is called a pheochromocytoma, and the thyroid tumor is a medullary carcinoma of the thyroid.

The tumors involve multiple parts of the thyroid gland or more than one of the parathyroid and adrenal glands. Tumors in the thyroid, adrenal, or parathyroid glands may occur years apart.

The disorder may occur at any age, and affects men and women equally. The main risk factor is a family history of MEN II.

There are two subtypes of MEN II -- MEN IIa and IIb. MEN IIb is less common.

Symptoms

The symptoms may vary. However, they are similar to those of:

Signs and tests

To diagnose this condition, the health care provider looks for a mutation in the RET gene. This can be done with a blood test. Additional tests are done to determine which hormones are being overproduced.

A physical examination may reveal:

Imaging tests used to identify tumors may include:

Blood tests are used to evaluate the function of each endocrine gland. The following tests may be performed:

Other tests or procedures that may be done include:

Treatment

Surgery is needed to remove pheochromocytoma.

For medullary carcinoma of the thyroid, the thyroid gland and surrounding lymph nodes must be totally removed. Thyroid hormone replacement therapy is given after surgery.

If a child is known to carry the RET gene mutation, surgery to remove the thyroid before it becomes cancerous is considered. This should be discussed with a physician who is very familiar with this condition. It would be done at an early age (before age 5) in people with known MEN IIa, and before age 6 months in people with MEN IIb.

Expectations (prognosis)

Pheochromocytoma is usually not cancerous (benign). Medullary carcinoma of the thyroid is a very aggressive and potentially fatal cancer. However, early diagnosis and surgery can often lead to a cure.

Complications

The spread of cancerous cells is a possible complication.

Calling your health care provider

Call your health care provider if you notice symptoms of MEN II or if someone in your family receives such a diagnosis.

Prevention

Screening close relatives of people with MEN II may lead to early detection of the syndrome and related cancers.

References

Kronenberg HM. Plyglandular disorders. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 250.

National Comprehensive Cancer Network Clinical Practice Guidelines in Oncology: Neuroendocrine Tumors. National Comprehensive Cancer Network; 2009. Version 2.2009.

See also:

  • Disease

    Medullary carcinoma of thyroid

    Thyroid cancer - CT scan

    Medullary carcinoma of the thyroid is cancer of the thyroid gland that starts in cells that release a hormone called calcitonin. Such cells are called “C” cells.

  • Special Topic

    Metastasis

    Lymph node metastases, CT scan

    Metastasis is the movement or spreading of cancer cells from one organ or tissue to another. Cancer cells usually spread through the bloodstream or the .

  • Disease

    Thyroid nodule

    A thyroid nodule is a growth (lump) in the thyroid gland. The thyroid gland is located at the base of the neck.

  • Disease

    Pheochromocytoma

    Endocrine glands

    Pheochromocytoma is a rare of adrenal gland tissue. It results in the release of too much epinephrine and norepinephrine, hormones that control , metabolism, and blood pressure .

Review date:
March 2, 2010
Reviewed by:
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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