Pituitary Tumors

Pituitary tumors often aren’t noticed or aren’t detected. In many cases, that’s because the symptoms caused by pituitary tumors that make hormones, called functioning adenomas, and large tumors, called macroadenomas, are similar to those of other medical conditions. It’s also because they grow very slowly over time. Small pituitary tumors that don’t make hormones, called nonfunctioning microadenomas, often don’t cause symptoms. If they are detected, it’s typically because of an imaging exam, such as an MRI or a CT scan, that’s done for another reason.

To detect and diagnose a pituitary tumor, your health care provider will likely talk with you about your personal and family medical history and do a physical exam. Testing to detect a pituitary tumor also may include:

• Blood tests. Blood tests can show whether your body has too much or too little of certain hormones. For some hormones, blood test results that show too much of the hormone may be all that’s needed for your health care provider to diagnose a pituitary adenoma.

  For other hormones, such as cortisol, a blood test result that shows too much of the hormone may need to be followed by other tests. Those tests can show if the earlier result was caused by a pituitary adenoma or by another health concern.

  Results that show hormone levels are too low need to be followed with other tests, usually imaging exams, to see if a pituitary adenoma may be the cause of those test results.

• Urine tests. A urine test may be used to help diagnose a pituitary adenoma that’s making too much of the hormone ACTH. Too much ACTH leads to too much cortisol in the body and causes Cushing disease.
• MRI scan. A magnetic resonance imaging scan, also called an MRI scan, is a test that uses a magnetic field and computer-generated radio waves to create detailed images of the body’s organs and tissues. An MRI of the brain can help detect a pituitary tumor and show its location and size.
• CT scan. A computed tomography scan, also called a CT scan, is a type of imaging test that combines a series of X-rays to create cross-sectional images. MRI scans are used more often than CT scans to detect and diagnose pituitary tumors. But a CT scan may be helpful in planning surgery if your health care provider tells you that a pituitary tumor must be removed.
• Vision testing. A pituitary tumor can affect eyesight, especially side vision, also called peripheral vision. Testing your eyes to check how well you can see may help your health care provider decide if other tests may be needed to detect a pituitary tumor.

Your health care provider may refer you to a specialist in hormone disorders, called an endocrinologist, for more testing.