What are pituitary tumors?
The pituitary gland is a small, pea-sized organ in the brain. It is located behind the back of the nose. It makes hormones that affect many other glands in your body. Most pituitary tumors are not cancerous. But because of where the gland is located, many tumors will press against the optic nerves. This can cause vision problems. Also tumors that make a lot of hormone will make the other endocrine glands make more hormones. That will cause symptoms related to the specific hormone.
Most pituitary tumors do not cause symptoms. As a result, they are not diagnosed. Or they are found only during a routine brain imaging test. Up to 1 in 4 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 do not make extra hormone. Until they become a certain size, you may not have any symptoms. When the tumor is large enough, it may cause headaches and vision problems.
Prolactin-producing tumors (prolactinomas)
These benign tumors are also common. They make too much prolactin. If you are a woman, high prolactin levels can cause your menstrual period to be irregular or to stop. These tumors can also cause you to make breast milk. If you are a man, you may have erectile dysfunction or a lack of interest in sex. You may also have enlarged breasts, infertility, or less body hair. In time, you may have headaches and vision problems.
Adrenocorticotropic hormone-producing tumors
ACTH stimulates the adrenal gland to make glucocorticoids. These are steroids that affect metabolism. They act as anti-inflammatory chemicals. They also suppress your immune system. Too much ACTH can cause Cushing's disease. The disease causes a buildup of fat in your face, neck, back, 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 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, an excess of 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
- Pain in the joints
Thyroid-stimulating hormone-producing tumors
Thyroid-stimulating hormone is made by these tumors. They can become large and spread. Symptoms may include:
- Fast heart rate
- Unintended weight loss
- Increased appetite
- Feelings of being warm or hot, or not tolerating heat
- Trouble falling asleep
- Feeling anxious
- Frequent bowel movements
- A lump in the front of the neck, due to an enlarged thyroid gland
Cancerous pituitary tumors are rare. They are usually found in older people. But they can occur at any age. These tumors often make hormones, just like many benign pituitary tumors do. In most cases, the only way to tell a cancerous tumor from a benign one is when the tumor spreads to another part of the body several years later.