What is the definition of Prolactinoma?

A prolactinoma is a noncancerous (benign) pituitary tumor that produces a hormone called prolactin. This results in too much prolactin in the blood.

What are the alternative names for Prolactinoma?

Adenoma - secreting; Prolactin - secreting adenoma of the pituitary

What are the causes for Prolactinoma?

Prolactin is a hormone that triggers the breasts to produce milk (lactation).

Prolactinoma is the most common type of pituitary tumor (adenoma) that produces a hormone. It makes up about 30% of all pituitary adenomas. Almost all pituitary tumors are noncancerous (benign). Prolactinoma may occur as part of an inherited condition called multiple endocrine neoplasia type 1 (MEN 1).

Prolactinomas occur most commonly in people under age 40. They are more common in women than in men, but are rare in children.

At least half of all prolactinomas are very small (less than 1 centimeter or 3/8 of an inch in diameter). These small tumors occur more often in women and are called microprolactinomas.

Larger tumors are more common in men. They tend to occur at an older age. The tumor can grow to a large size before symptoms appear. Tumors larger than 3/8 inch (1 cm) in diameter are called macroprolactinomas.

The tumor is often detected at an earlier stage in women than in men because of irregular menstrual periods.

What are the symptoms for Prolactinoma?

In women:

  • Abnormal milk flow from the breast in a woman who is not pregnant or nursing (galactorrhea)
    Abnormal milk flow from the breast in a woman who is not pregnant or nursing (galactorrhea)
  • Breast tenderness
    Breast tenderness
  • Decreased sexual interest
    Decreased sexual interest
  • Decreased peripheral vision
    Decreased peripheral vision
  • Headache
  • Infertility
  • Stopping of menstruation not related to menopause, or irregular menstruation
  • Vision changes

In men:

  • Decreased sexual interest
    Decreased sexual interest
  • Decreased peripheral vision
    Decreased peripheral vision
  • Enlargement of breast tissue (gynecomastia)
  • Headache
  • Erection problems (impotence)
  • Infertility
  • Vision changes

Symptoms caused by pressure from a larger tumor may include:

  • Headache
  • Lethargy
  • Nasal drainage
  • Nausea and vomiting
  • Problems with the sense of smell
  • Sinus pain or pressure
  • Vision changes, such as double vision, drooping eyelids or visual field loss

There may be no symptoms, especially in men.

What are the current treatments for Prolactinoma?

Medicine is usually successful in treating prolactinoma. Some people have to take these medicines for life. Other people can stop taking the medicines after a few years, especially if their tumor was small when it was discovered or has disappeared from the MRI. But there is a risk that the tumor may grow and produce prolactin again, especially if it was a large tumor.

A large prolactinoma can sometimes get larger during pregnancy.

Surgery may be done for any of the following:

  • Symptoms are severe, such as a sudden worsening of vision
  • You are not able to tolerate the medicines to treat the tumor
  • The tumor does not respond to medicines

Radiation is usually only used in people with prolactinoma that continues to grow or gets worse after both medicine and surgery have been tried. Radiation may be given in the form of:

  • Conventional radiation
  • Gamma knife (stereotactic radiosurgery) -- a type of radiation therapy that focuses high-powered x-rays on a small area in the brain.

What is the outlook (prognosis) for Prolactinoma?

The outlook is usually excellent, but depends on the success of medical treatment or surgery. Getting tested to check whether the tumor has returned after treatment is important.

Treatment for prolactinoma may change the levels of other hormones in the body, especially if surgery or radiation is performed.

High levels of estrogen or testosterone may be involved in the growth of a prolactinoma. Women with prolactinomas should be followed closely during pregnancy. They should discuss this tumor with their provider before taking birth control pills with a higher than usual estrogen content.

When should I contact a medical professional for Prolactinoma?

See your provider if you have any symptoms of prolactinoma.

If you have had a prolactinoma in the past, call your provider for a general follow-up, or if your symptoms return.



Bronstein MD. Disorders of prolactin secretion and prolactinomas. In: Jameson JL, De Groot LJ, de Kretser DM, et al, eds. Endocrinology: Adult and Pediatric. 7th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 7.

Tirosh A, Shimon I. Current approach to treatments for prolactinomas. Minerva Endocrinol. 2016;41(3):316-323. PMID: 26399371 www.ncbi.nlm.nih.gov/pubmed/26399371.

  • Condition: Refractory Prolactinoma Resistant to Dopamine Agonists
  • Journal: Frontiers in endocrinology
  • Treatment Used: Temozolomide
  • Number of Patients: 1
  • Published —
This case report evaluated the use of temozolomide (TMZ) treatment for refractory prolactinoma resistant to dopamine agonists.
  • Condition: Lactotroph Adenomas (LAs)
  • Journal: Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia
  • Treatment Used: Gamma Knife Radiosurgery (GKRS)
  • Number of Patients: 52
  • Published —
This study evaluated the effectiveness of gamma knife radiosurgery (painless computer-guided treatment that delivers highly focused radiation to tumors and lesions in the brain; GKRS) for high-risk lactotroph adenomas (noncancerous tumors of the pituitary gland; LAs).