A pituitary tumor is an abnormal growth that develops within the pituitary gland. The pituitary is a pea-sized gland at the base of the brain. It secretes hormones into the bloodstream. These hormones control most of the other glands in the body that secrete hormones.
The pituitary gland has three parts or lobes.
Pituitary tumors comprise about 10% of all brain tumors. They generally develop from the anterior lobe and are rarely caused by cancer. When the tumor enlarges, it generally grows upward. It can press on other structures, such as the optic nerves. The optic nerves carry visual signals, so vision is often affected. Pituitary tumors can also interfere with:
The exact cause of pituitary tumors is unknown. Women face a higher risk of developing pituitary tumors than men.
A pituitary tumor can cause symptoms that fall into two groups:
General symptoms include:
Depending on the cell type making up the tumor, symptoms may include:
Diagnosis of a pituitary tumor begins with a history and physical exam. The healthcare provider may order tests, including:
There is no known way to prevent pituitary tumors.
Pituitary tumors enlarge at varying rates. Untreated tumors may eventually lead to blindness by damaging the optic nerves. After 75% of normal pituitary cells are destroyed, all pituitary function may eventually be lost.
Pituitary tumors are not contagious, and pose no risk to others.
Many pituitary tumors can be removed surgically. The operation usually takes place through the head for larger tumors and through the nose for smaller ones. Radiation therapy can shrink some tumors. Medicines, such as bromocriptine, can shrink certain tumors that affect breast milk production.
Surgery carries a risk of bleeding, infection, or allergic reaction to anesthesia.
Treatment, even if successful, may not correct the visual impairment. Most people will require some form of hormone replacement medicine, even after successful surgery.
The individual will have regular visits with the healthcare provider. Any new or worsening symptoms should be reported to the provider.
Author:James Warson, MD
Date Written:
Editor:Crist, Gayle P., MS, BA
Edit Date:08/10/01
Reviewer:William M. Boggs, MD
Date Reviewed:08/13/01
http://www.nci.nih.gov