Last Modified : 2006-02-02
Pituitary tumors are tumors found in the pituitary gland, a small organ about the size of a pea in the center of the brain just above the back of the nose. The pituitary gland makes hormones that affect growth and the functions of other glands in the body. Pituitary tumors may be grouped as follows:
These pituitary tumors may be either functioning or nonfunctioning. Tumors that make one or more of the pituitary hormones are called functioning tumors, while those that do not make hormones are called nonfunctioning tumors. Each type of functioning tumor causes different symptoms, depending on the type of hormone that is being made by the tumor. Symptoms may also be caused if the tumor grows large and presses on nearby parts of the brain. A doctor should be seen if there are symptoms such as these:
Some cancers in other parts of the body may metastasize (spread) to the pituitary gland, but these pituitary tumors usually do not cause symptoms. Breast and lung cancer are the most common types of cancer that spread to the pituitary.
If there are symptoms, a doctor may order laboratory tests to see what the hormone levels are in the blood. The doctor may also order an MRI (magnetic resonance imaging) scan, which uses magnetic waves to make a picture of the inside of the brain. Other special x-rays may also be done.
Pituitary tumors are classified according to size:
Most pituitary adenomas are microadenomas.
Once a pituitary tumor is found, more tests will be done to find out how far the tumor has spread, the type of tumor, and whether or not it makes hormones. A doctor needs to know the type of tumor to plan treatment. The following types of pituitary tumors are found:
These tumors make prolactin, a hormone that stimulates a woman’s breasts to make milk during and after pregnancy. Prolactin-secreting tumors can cause the breasts to make milk and menstrual periods to stop when a woman is not pregnant. In men, prolactin-producing tumors can cause impotence.
These tumors make a hormone called adrenocorticotropic hormone (ACTH), which stimulates the adrenal glands to make glucocorticoids. When the body makes too much ACTH, it causes Cushing’s disease. In Cushing's disease, fat builds up in the face, back, and chest, and the arms and legs become very thin. Another symptom of ACTH-producing tumors is weakened bones.
These tumors make growth hormone. Too much growth hormone can cause acromegaly (the hands, feet, and face are larger than normal) or gigantism (the whole body grows much larger than normal).
Nonfunctioning tumors do not produce hormones. Symptoms such as headache or trouble seeing may be caused by the tumor pressing on nearby brain tissue. If the tumor presses on or destroys parts of the pituitary gland, the pituitary gland may stop making one or more of its hormones. Lack of a certain hormone will affect the work of the gland or organ that the hormone controls. For example, if the pituitary gland stops making the hormone that affects the ovaries, the ovaries will not work normally or will not develop normally in a child.
These tumors make thyrotrophin, which stimulates the thyroid gland to make thyroid hormone. The thyroid hormone helps regulate heart rate, body temperature, the level of calcium in the blood, and the rate at which food is changed into energy. Too much thyroid hormone can cause rapid heartbeat, weight loss, and other symptoms. Thyroid hormone-producing tumors may be large and may spread. They sometimes also make growth hormone and/or prolactin.
These tumors usually grow quickly and make hormones, commonly ACTH and prolactin. Symptoms may be caused by the hormone that is made by the tumor and by the tumor pressing on nearby brain tissue.
For information about other types of pituitary tumors, refer to the following PDQ summaries:
Recurrent disease means that the tumor has come back (recurred) after it has been treated. It may come back in the pituitary gland or in another part of the body.
There are treatments for all patients with pituitary tumors. Three kinds of treatment are used:
Surgery is a common treatment of pituitary tumors. A doctor may remove the tumor using one of the following operations:
Radiation therapy uses high-energy x-rays to kill cancer cells and shrink tumors. Radiation for pituitary tumors usually comes from a machine outside the body (external radiation therapy). Clinical trials are testing stereotactic radiation surgery, in which radiation is aimed to the tumor only, with less damage to healthy tissue. A CT scan or MRI is used to find the exact location of the tumor. A rigid head frame is attached to the skull and high-dose radiation is directed to the tumor through openings in the head frame, so only a small amount of normal brain tissue is affected. This procedure does not involve surgery. Radiation therapy may be used alone or in addition to surgery or drug therapy.
Drug therapy is the use of drugs to stop the pituitary gland from making too many hormones.
Treatments for pituitary tumors depend on the type of tumor, the symptoms of its hormone activity, how far the tumor has spread into the brain, and the patient’s age and overall health.
Standard treatment may be considered because of its effectiveness in patients in past studies, or participation in a clinical trial may be considered. Not all patients are cured with standard therapy and some standard treatments may have more side effects than are desired. For these reasons, clinical trials are designed to find better ways to treat cancer patients and are based on the most up-to-date information. Clinical trials are ongoing in some parts of the country for patients with pituitary tumors. Information about ongoing clinical trials is available from the NCI Web site. To learn more about clinical trials, call the Cancer Information Service at 1-800-4-CANCER (1-800-422-6237); TTY at 1-800-332-8615.
Treatment may be one of the following:
Treatment may be one of the following:
Treatment may be one of the following:
Treatment is usually palliative, to relieve symptoms and improve the patient's quality of life. Treatment may be one of the following:
Treatment of recurrent pituitary tumor depends on the type of tumor, the type of treatment the patient has already had, and other factors such as the patient’s general condition. Patients may want to take part in a clinical trial of new treatments. Treatment may be one of the following: