What are pituitary tumors?
A pituitary tumor is an abnormal growth in the pituitary gland. The pituitary is a small gland in the brain. It is located behind the back of the nose. It makes hormones that affect many other glands and many functions in your body. Most pituitary tumors are not cancerous (benign). They don’t spread to other parts of your body. But they can cause the pituitary to make too few or too many hormones, causing problems in the body.
Pituitary tumors that make too many hormones will cause other glands to make more hormones. That will cause symptoms related to each of the specific hormones. Many pituitary tumors will also press against the nearby optic nerves. This can cause vision problems.
Most pituitary tumors don’t cause symptoms. As a result, they are not diagnosed. Or they are found only during a routine brain imaging test. About 25% of people may have small pituitary tumors without knowing it.
Below are the main types of pituitary tumors.
Nonfunctional adenomas (null cell adenomas)
These tumors are the most common type. They don’t make extra hormone. You may not have any symptoms until the tumor is a certain size. When the tumor is big enough, it may cause headaches and vision problems. Large pituitary tumors can crush normal pituitary cells. This leads to symptoms caused by decreased hormone production.
Prolactin-producing tumors (prolactinomas)
These benign tumors are also common. They make too much prolactin. If you are a woman, high prolactin levels can make your menstrual period irregular, or even stop your period. These tumors can also cause you to make breastmilk, even if you are not pregnant or nursing. If you are a man, you may have erectile dysfunction or a lack of interest in sex. You may also have enlarged breasts, a low sperm count, or less body hair. In time, you may have headaches and vision problems.
ACTH (adrenocorticotropic hormone) stimulates the adrenal gland to make steroids that affect metabolism. These are called glucocorticoids. They reduce redness and swelling (inflammation) all over the body. They also slow down your immune system. Too much ACTH can cause Cushing's disease. This disease causes fat buildup in your face, neck, back, belly (abdomen), and chest. Also your arms and legs tend to become thin. You may also have purple stretch marks and high blood pressure. These tumors can also weaken your bones.
Growth hormone-producing tumors
These tumors make too much growth hormone. In children, too much growth hormone stimulates the growth of almost all the bones in the body. When that occurs, the result is called gigantism. Gigantism can include increased height (over 7 feet), very quick growth, joint pain, and heavy sweating. In adults, too much growth hormone causes a condition called acromegaly. It may include:
- Extra growth in the skull, hands, and feet
- Deepened voice
- A change in the facial appearance because of extra growth in the facial bones
- A wide spacing of teeth because of the growth of facial bones
- Joint pain
- Snoring or sleep apnea
- Diabetes or impaired glucose tolerance