PITUITARY GLAND AND MEN1

THE PITUITARY GLAND

The pituitary, a small gland located at the base of the brain, produces many important hormones that regulate basic body functions.

The normal major pituitary hormones are

• Prolactin – controls the formation of breast milk and influences fertility and bone strength
• Growth Hormone – regulates body growth, especially during adolescence
• ACTH – stimulates the adrenal glands to produce cortisol
• Thyrotropin – stimulates the thyroid gland to produce thyroid hormones, which regulate metabolism
• Luteinizing Hormone – stimulates the ovaries or testes to produce sex hormones
• FSH – regulates fertility

PROLACTINOMAS

The pituitary gland becomes overactive in about one in four people with MEN1. This overactivity can usually be traced to a small tumor in the gland that releases too much prolactin, called a prolactinoma. High prolactin levels can cause excessive production of breast milk or interfere with fertility in women or with sex drive and fertility in men.

Treatment may not be needed for prolactinomas. If treatment is needed, a medicine known as a dopamine agonist can effectively shrink the tumor and lower the production of prolactin. Occasionally, prolactinomas do not respond well to this medication. In such cases, surgery, radiation, or both may be needed.

RARE PITUITARY COMPLICATIONS

Rarely, MEN1 creates pituitary tumors that release high amounts of ACTH, which in turn stimulates the adrenal glands to produce excess cortisol. Too much cortisol can lead to muscle weakness, weakened bones and fractures, and thinning skin, among other problems. Pituitary tumors that produce growth hormone cause excessive bone growth or disfigurement. In general, surgery is the mainstay of treatment for these uncommon types of tumors.

Source: National Endocrine and Metabolic Diseases Information Service (NEMDIS), a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK); National Institutes of Health (NIH).