Multiple endocrine neoplasia (MEN) I

  • Definition
    • Multiple endocrine neoplasia (MEN) type I is a disease in which one or more of the endocrine glands are overactive or forms a tumor. It is passed down through families.

      Endocrine glands most commonly involved include:

      • Pancreas
      • Parathyroid
      • Pituitary
  • Alternative Names
    • Wermer syndrome; MEN I

  • Causes
    • MEN I is caused by a defect in a gene that carries the code for a protein called menin. The condition causes tumors of various glands to appear in the same person, but not necessarily at the same time.

      The disorder may occur at any age, and it affects men and women equally. A family history of this disorder raises your risk.

  • Symptoms
  • Exams and Tests
  • Treatment
    • Surgery to remove the diseased gland is often the treatment of choice. A medicine called bromocriptine may be used instead of surgery for pituitary tumors that release the hormone prolactin.

      The parathyroid glands, which control calcium production, can be removed. However, it is difficult for the body to regulate calcium levels without these glands, so a total parathyroid removal is not done first in most cases.

      Medicine is available to decrease the excess stomach acid production caused by some tumors (gastrinomas), and to reduce the risk of ulcers.

      Hormone replacement therapy is given when entire glands are removed or do not produce enough hormones.

  • Outlook (Prognosis)
    • Pituitary and parathyroid tumors are usually noncancerous (benign), but some pancreatic tumors may become cancerous (malignant) and spread to the liver. These can lower life expectancy.

      The symptoms of peptic ulcer disease, low blood sugar, excess calcium in the blood, and pituitary dysfunction usually respond well to appropriate treatment.

  • Possible Complications
    • The tumors can keep coming back. Symptoms and complications depend on which glands are involved. Regular check-ups by your health care provider are essential.

  • When to Contact a Medical Professional
    • Call your provider if you notice symptoms of MEN I or have a family history of this condition.

  • Prevention
    • Screening close relatives of people affected with this disorder is recommended.

  • References
    • National Comprehensive Cancer Network. Clinical practice guidelines in oncology: neuroendocrine tumors. National Comprehensive Cancer Network; 2014. Updated May 25, 2016. Version 1.2015. Accessed April 6, 2016.

      Nieman LK, Spiegel AM. Polyglandular disorders. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 231.

      Thakker RV. Multiple endocrine neoplasia type 1. In: Jameson JL, De Groot LJ, de Kretser DM, et al, eds. Endocrinology: Adult and Pediatric. 7th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 148.