A prolactinoma is a benign pituitary tumor that makes the hormone prolactin. While these tumors aren’t life threatening, they can cause fertility challenges and vision problems. Most are treated with medications.

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Pituitary tumors affect your pituitary gland, which is responsible for making many different hormones in your body.

Healthcare professionals diagnose over 10,000 pituitary tumors in the United States each year. The vast majority of these tumors are benign (noncancerous).

Continue reading to learn more about prolactinomas, their symptoms, and how they’re diagnosed and treated.

A prolactinoma is a benign tumor that affects the pituitary gland. The pituitary gland is found at the base of your brain and makes several different hormones, such as growth hormone, thyroid-stimulating hormone, and prolactin.

Prolactinomas account for about 40% of all pituitary tumors. These tumors make too much of the hormone prolactin.

Prolactin is the hormone that leads to milk production during pregnancy and nursing. Having too much prolactin in your body can lead to health issues.

Doctors classify prolactinomas according to their size:

  • Microprolactinomas are the most common type and are less than 10 millimeters (mm) in diameter.
  • Macroprolactinomas have a diameter of 10 mm or more.
  • Giant prolactinomas are more than 40 mm in diameter.

Increased prolactin levels can have a variety of health effects. Some symptoms can be different depending on your sex.

For example, according to 2022 research, females can have symptoms that include abnormal breast milk production and periods that are irregular or that stop altogether. Males can experience erectile dysfunction.

Other potential symptoms related to high prolactin levels include low libido and fertility issues.

Prolactinomas can press on surrounding tissues, which may lead to additional symptoms like:

The exact cause of prolactinomas is unknown. In general, tumors happen due to DNA changes that lead to increased growth and division of cells.

In some situations, inherited genetic conditions may contribute to their development. For example, 15% to 60% of people with multiple endocrine neoplasia type 1 have pituitary tumors, many of which are prolactinomas.

Women are also more likely to develop prolactinomas than men.

A blood test can detect if the levels of prolactin in your blood are higher than normal. But there are many other things that can lead to higher prolactin levels. These include but aren’t limited to:

Because of this, your doctor will want to get a very thorough medical history. They’ll ask about your symptoms, your personal and family health history, and any medications you’re taking. They’ll also do a physical exam.

MRIs and CT scans can confirm the presence of a pituitary tumor.

Some prolactinomas don’t need to be treated immediately, especially if they’re not causing symptoms. Instead, a doctor will use blood tests and imaging to periodically check prolactin levels and tumor size.

If you’re experiencing symptoms and need treatment, your doctor may prescribe dopamine agonists. These medications can help manage prolactin levels and shrink the tumor. Examples of dopamine agonists include bromocriptine (Parlodel, Cycloset) and cabergoline.

If a prolactinoma doesn’t respond to medications, your doctor may recommend surgery to remove the tumor. Radiation therapy is another treatment option for prolactinomas that can’t be effectively treated with medications or surgery.

If your prolactinoma responds to medications, you may need to continue to take medication for the rest of your life to manage your prolactin levels and prevent the tumor from growing.

Some people may be able to stop taking medication if treatment is effective for at least 2 years and imaging tests no longer detects the tumor.

Overall, the outlook for prolactinomas is very good. These tumors can typically be treated easily with medications.

In a 2022 study of 107 people with prolactinomas treated with medications, 13 people (about 12%) had complete resolution of their tumor.

How serious is a prolactinoma?

A prolactinoma is a benign tumor and isn’t life threatening. However, these tumors can cause a variety of health issues, including fertility challenges and vision issues.

Is a prolactinoma considered a brain tumor?

There’s some debate on this topic. Some doctors may classify pituitary tumors as brain tumors. However, the Pituitary Foundation notes that while the pituitary gland is near the brain, it’s not actually a part of the brain.

What does a prolactinoma headache feel like?

Headache due to a pituitary tumor is most often felt around the forehead, and it can affect one or both sides of the head. It can feel similar to other primary headache disorders, such as migraine, making it difficult to diagnose.

A prolactinoma is a benign pituitary tumor that makes the hormone prolactin. Having prolactin levels that are higher than normal can lead to issues with fertility as well as vision problems.

Prolactinomas are typically treated with medications. When a tumor doesn’t respond well to medications, surgery may be needed to remove the tumor.

Prolactinomas aren’t life threatening. Most tumors are small and can be managed with medications. Larger prolactinomas are generally more difficult to treat.