A prolactinoma is a benign (noncancerous) tumor of the pituitary gland, which is located at the base of the brain. The pituitary gland is sometimes called the “master gland” and is responsible for producing a number of important hormones involved with growth, metabolism, blood pressure, and reproduction.
One of these hormones is prolactin. In women, prolactin helps with the production of breast milk. Men’s bodies make prolactin, but the hormone doesn’t have a known purpose for them.
Prolactinomas make excessive amounts of prolactin. High levels of prolactin in the blood can reduce levels of the sex hormones estrogen and testosterone.
While the tumor itself is benign, the high levels of prolactin it produces can cause serious problems for both men and women.
A woman with a prolactinoma may start having changes in her menstrual periods. Her breasts might start to produce milk, even if she is not pregnant or nursing. She might become less interested in sex. Vaginal dryness may also occur, as estrogen is important for vaginal lubrication. Some women with prolactinomas have trouble becoming pregnant.
A man with a prolactinoma might develop erectile dysfunction.
Other symptoms include headaches and vision problems. These may occur if the tumor grows large enough to compress the optic nerves, which are close to the pituitary gland.
Prolactinomas can often be treated with medication. If this doesn’t work, surgery to remove the tumor is another option. In rare cases, radiation might be used. Sexual problems usually get better once the tumor is treated and prolactin levels return to normal.
Prolactinomas are the most common type of pituitary gland tumor, but it’s not common for them to cause symptoms. Women are more likely to get prolactinomas than men are. Scientists aren’t sure exactly why prolactinomas develop.
Men and women who are concerned about prolactinomas should see their healthcare professional. Diagnosing a prolactinoma usually involves a blood test to measure prolactin levels. Imaging tests, such as magnetic resonance imaging (MRI) or a computerized tomography (CT) scan are usually ordered so that the doctor can get a closer look at the pituitary gland and the surrounding area. Sometimes, a vision test is also done.