What Are Pituitary Gland Tumors?

Medically Reviewed by Sabrina Felson, MD on February 21, 2024
4 min read

It’s only about the size of a pea, but your pituitary gland controls a lot of important stuff, like your growth, heart rate, and ability to have kids. It’s sometimes called the master gland because it tells your other glands when to make more hormones. Those hormones then move throughout your body and tell your organs what they need to do to keep everything in working order.

A pituitary gland tumor is a group of abnormal cells that grows out of control in your pituitary gland. Most of these tumors are not cancerous. Pituitary cancer is very rare.

Still, the tumors can cause serious problems, either because of their size (large tumors) or because they make extra hormones your body doesn’t need (functioning tumors). They’re typically treated with surgery, medicine, or radiation.

Doctors aren’t sure what causes pituitary tumors. The genes of some pituitary cells change at the start, but the change seems to happen at random.

When you have a genetic condition, you have a defect in one or more genes. Some conditions may make you more likely to get pituitary tumors, such as:

  • Carney complex (rare genetic disorder that causes many noncancerous tumors)
  • Familial isolated pituitary adenoma, or FIPA (rare condition that makes your body grow larger than normal)
  • Isolated familial acromegaly (similar to FIPA)
  • McCune-Albright syndrome (rare condition of that shows up as abnormalities in your bones and skin)
  • Multiple endocrine neoplasia, type I and type IV (MEN1, MEN4) (Disorders that can cause tumors in your glands)

The pituitary gland is tucked in a small area just below your brain. It’s very close to the optic nerves, which carry messages between the brain and eyes. There’s not much room for anything else in there, so large tumors cause issues just because of their size.

Large tumors put pressure on the area around the pituitary gland and cause:

They can also press on the pituitary gland, causing it to make fewer hormones. That can lead to:

  • Breast growth, less facial hair, and trouble getting erections (men)
  • Feeling cold
  • Fewer menstrual periods or no breast milk (women)
  • Growth and sexual development delays (children)
  • Low sex drive
  • Throwing up
  • Upset stomach
  • Weight changes

Functioning tumors, which actually make hormones, can also lead to problems. If you have one of these tumors, your symptoms will depend on which hormone it makes:

Adrenocorticotropic hormone (ACTH) controls how much cortisol hormone your body makes. Too much cortisol can lead to Cushing’s syndrome, with symptoms like:

Growth hormone manages how you grow and use sugar and fat. Too much may cause:

  • Children to grow much taller than normal, called gigantism
  • Face, hand, and foot bones to grow in adults, called acromegaly
  • Heart problems
  • High blood sugar
  • Joint pain
  • Sweating much more than normal

Prolactin causes breast milk to flow in women. Too much can cause:

Among men, too much prolactin can cause low sperm count and trouble getting erections.

Thyroid-stimulating hormone (TSH) tells the thyroid to make hormones that control growth, temperature, and heart rate. Too much can cause:

Your doctor will first ask questions about your symptoms and health history, then give you a physical exam.

You may also get:

  • Eye exams to see if the tumor affects your vision
  • Neurological exam to test how your brain, spinal cord, and nerves are working
  • Blood and urine tests to check your hormone levels
  • Imaging to look inside your body for a tumor (usually CT scan, but sometimes MRI)

Many tumors don’t need treatment. If yours does, how it’s treated depends on the kind of tumor, its size, and your overall health. For cancerous tumors, doctors generally use both surgery and radiation.

Surgery to remove the tumor is the most common treatment unless you have one that makes prolactin. To perform the surgery, your doctor may go in through the nose, an opening made above the upper lip, or an opening made in the skull. Typically, doctors go through the skull for larger tumors or ones that have spread in a complex way.

Radiation therapy destroys the tumor with high energy X-rays. It’s helpful when surgery can’t remove the whole tumor, or if the tumor returns and medicine doesn’t improve your symptoms. There are different types of radiation, from a high dose you get just once through a very precise process (doctors call this “stereotactic radiosurgery”) to smaller doses you get several times a week for 4 to 6 weeks.

Medicine. Your doctor may try this first, depending on what type of tumor you have. If your tumor makes prolactin, medicine can lower the amount it produces and cause it to shrink. Drugs can also be helpful on tumors that make growth hormone, and in managing Cushing’s syndrome and acromegaly.