Pituitary adenomas are tumors that start in your pituitary gland. They’re usually noncancerous and grow slowly. Prolactinomas are pituitary adenomas that secrete the hormone prolactin.

Pituitary adenomas are relatively common tumors that are usually benign (noncancerous). Prolactinomas are a type of pituitary adenoma that secretes a hormone called prolactin.

Pituitary adenomas sometimes have no symptoms, and people can live with them all their lives. Prolactinomas, on the other hand, typically cause hormone-related symptoms, like menstrual changes and decreased sex drive.

Anywhere from 46% to 78% of pituitary adenomas secrete hormones. They can secrete other hormones too, but prolactin is one of the most common. Estimates suggest that prolactinomas make up about 40% of pituitary adenomas.

Pituitary adenomas can also secret other hormones, such as:

Read on to learn more about how the symptoms, treatment, and outlook of pituitary adenomas and prolactinomas differ.

Pituitary adenomas often develop spontaneously, meaning they have no known cause. Only about 5% of people with pituitary adenomas are considered genetic.

These tumors are most commonly diagnosed in people in their 30s or 40s.

Many pituitary adenomas are discovered during imaging tests conducted for unrelated reasons. They’re usually noncancerous and tend to grow slowly. Despite not being cancerous, they can cause problems if they secrete hormones or grow large and compress structures in your brain.

Autopsy studies have suggested that small, non-symptomatic adenomas might affect more than 16% of people.

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Many different symptoms can develop, but they can include:


Adenomas often don’t require treatment, but your doctor will likely want to track how your tumor is changing over time with imaging.

If your tumor is causing symptoms, it will likely need to be removed surgically. Transsphenoidal resection is often the surgical technique of choice. This procedure involves removing the tumor through the hollow bone in the back of your nose.

Large adenomas may need to be removed with craniotomy. This procedure involves removing a flap of bone in your skull and cutting the protective layer surrounding your brain. It’s a more extensive procedure.

Medications may help shrink your tumor and reduce excess hormone levels.


Many adenomas have excellent outlooks if they don’t secrete hormones (non-functioning adenomas). Tumors that produce hormones can cause complications, but many people live normal lifespans with little to no long-term effects.

Prolactinomas are pituitary adenomas that secret the hormone prolactin. Prolactin is a hormone that causes breast growth and milk production in pregnant people and those who have recently given birth. It has no known function in males.

Prolactinomas are about 3 times more common in females than males and are most commonly diagnosed between the ages of 25 and 34.

Rarely, some prolactinomas secrete other hormones like ACTH or TSH. About 10% of prolactinomas secret growth hormone.

Signs and symptoms of prolactinoma in people assigned female at birth include:

Signs and symptoms of a prolactinoma in people assigned male at birth may include:

Prolactinomas rarely occur in children and adolescents. When they do, they can cause delayed puberty or growth delays.


Unlike other types of pituitary adenomas, prolactinomas often respond well to medications and are rarely treated surgically. Medications called dopamine agonists may:

  • return your prolactin levels back to normal
  • shrink your tumor
  • correct symptoms caused by your tumor

The two most common types of dopamine agonists used to treat prolactinomas are bromocriptine and cabergoline.

If medications aren’t effective at treating your symptoms, your doctor may recommend surgery or radiation therapy.


Most people with small prolactinomas have an excellent outlook with regular medication. But the growth of large tumors can be aggressive and unpredictable. About 80% of people with small prolactinomas respond to medications.

Craniopharyngiomas are rare tumors that usually form near your pituitary gland. Like pituitary adenomas, they usually aren’t cancerous, and the cause usually isn’t known. They tend to be most common in children and adults over 50.

Also, like pituitary adenomas, craniopharyngiomas can cause problems if they grow large or secret hormones. As many as 61% of people with craniopharyngiomas develop obesity.

Craniopharyngiomas are much rarer than pituitary adenomas. According to the American Association of Neurological Surgeons, they affect less than 2 people per 1 million.

Pituitary adenomas are a type of tumor that starts in your pituitary gland. They’re usually noncancerous and slow-growing. They can cause symptoms if they grow large and push on structures in your brain or if they secret hormones.

Prolactinomas are pituitary adenomas that secrets the hormone prolactin. They’re often well-controlled with medications called dopamine agonists. Dopamine agonists can shrink the tumor and reduce prolactin levels.