Multiple endocrine neoplasia (MEN) I: MedlinePlus Medical Encyclopedia

P 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.
P Endocrine glands most commonly involved include:
- Pancreas
- Parathyroid
- Pituitary

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

T Symptoms
P Symptoms vary from person to person, and depend on which gland is involved. They may include:
- Abdominal pain
- Anxiety
- Black, tarry stools
- Bloated feeling after meals
- Burning, aching, or hunger discomfort in the upper abdomen or lower chest that is relieved by antacids, milk, or food
- Decreased sexual interest
- Fatigue
- Headache
- Lack of menstrual periods (in women)
- Loss of appetite
- Loss of body or facial hair (in men)
- Mental changes or confusion
- Muscle pain
- Nausea and vomiting
- Sensitivity to the cold
- Unintentional weight loss
- Vision problems
- Weakness

T Exams and Tests
P The health care provider will perform a physical exam and ask questions about your medical history and symptoms. The following tests may be done:
- Blood cortisol level
- CT scan of the abdomen
- CT scan of the head
- Fasting blood sugar
- Genetic testing
- Insulin test
- MRI of the abdomen
- MRI of the head
- Parathyroid biopsy
- Serum adrenocorticotropic hormone
- Serum calcium
- Serum follicle stimulating hormone
- Serum gastrin
- Serum glucagon
- Serum luteinizing hormone
- Serum parathyroid hormone
- Serum prolactin
- Serum thyroid stimulating hormone
- Ultrasound of the neck

T Treatment
P 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.
P 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.
P Medicine is available to decrease the excess stomach acid production caused by some tumors (gastrinomas), and to reduce the risk of ulcers.
P Hormone replacement therapy is given when entire glands are removed or do not produce enough hormones.

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

T Possible Complications
P 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.

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

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

T Alternative Names
P Wermer syndrome; MEN I

T Images
- Endocrine glands

T References
P National Comprehensive Cancer Network. Clinical practice guidelines in oncology: neuroendocrine tumors. National Comprehensive Cancer Network; 2014. Updated May 25, 2016. Version 1.2015. www.nccn.org/professionals/physician_gls/pdf/neuroendocrine.pdf. Accessed April 6, 2016.
P 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.
P 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.

T Review Date 3/16/2016
P Updated by: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

