Pituitary adenomas are tumors in the pituitary gland, located in the center of the head behind the eyes. The pituitary gland is less than a half inch in diameter and controls many of the body's hormones — chemicals that regulate essential body processes.
There are several types of pituitary tumors. Some tumors may cause Cushing's disease, in which too many hormones called glucocorticoids are released into the bloodstream. This causes fat to build up in the face, back and chest while the arms and legs become very thin. Other symptoms include too much sugar in the blood, weak muscles and bones, a flushed face and high blood pressure.
Other pituitary tumors can cause a condition called acromegaly, where the hands, feet and face are larger than normal. In very young people, the entire body may grow much larger than normal.
Almost all pituitary tumors are benign, rather than malignant or cancerous, and are relatively slow growing. They rarely spread to other areas of the body.
If a pituitary tumor exists, the pituitary gland may make an excessive amount of hormones. Tumors that make hormones are called functioning tumors and those that don't make hormones are called nonfunctioning tumors.
Tumors that secrete hormones tend to be smaller than the pituitary gland when they're diagnosed. In fact, most pituitary tumors are microadenomas that measure 3 to 9 millimeters in diameter. Less common tumors are macroadenomas that are 10 millimeters or larger in diameter.
Tumors that don't secrete hormones, called endocrine-inactive adenomas, tend to be larger and may compress other tissue such as the optic nerves, causing vision loss.
Patients with pituitary tumors may experience one or more of the following symptoms:
One type of pituitary tumor can cause a woman's breasts to produce milk even though she isn't pregnant and can stop her periods. Women may experience irregular or lack of periods and infertility, while men may have erectile dysfunction, loss of body or facial hair, loss of sexual drive and infertility.
Treatment options depend on the type of tumor and on its size. Certain medications can decrease tumor size as well as alleviate symptoms. In cases where the tumor is large, treatment can be with radiation therapy or surgery. Surgery is a common treatment for pituitary tumors. Trans-sphenoidal adenectomy surgery can often remove the tumor without affecting other parts of the brain.