Prolactinoma
Adenoma - secreting; Prolactin - secreting adenoma of the pituitary
A prolactinoma is a noncancerous (benign) pituitary tumor that produces a hormone called prolactin. This results in too much prolactin in the blood.
Causes
Prolactin is a hormone that triggers the breasts to produce milk (lactation).
Prolactinoma is the most common type of pituitary tumor (adenoma). It makes up at least 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)
Pituitary tumor
A pituitary tumor is an abnormal growth in the pituitary gland. The pituitary is a small gland at the base of the brain. It regulates the body's ba...
Multiple endocrine neoplasia type 1
Multiple endocrine neoplasia (MEN) type I is a disease in which one or more of the endocrine glands are overactive or forms a tumor. It is passed do...
Prolactinomas occur most commonly in people under age 40. They are about 5 times more common in women than in men, but are rare in children.
At least half of all prolactinomas are very small (less than 1 cm or 3/8 of an inch in diameter). These small tumors are more common in women.
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.
The tumor is often detected at an earlier stage in women than in men.
Low thyroid function (hypothyroidism) and medicines that treat mental illnesses can raise prolactin levels. Some illicit drugs like marijuana can also raise prolactin levels. Other pituitary tumors can also cause increased prolactin levels by causing increased prolactin secretion from the normal, healthy pituitary. This can cause symptoms similar to prolactinoma.
Symptoms
In women:
-
Abnormal milk flow from the breast in a woman who is not pregnant or nursing (
galactorrhea
)
Galactorrhea
Nipple discharge is any fluid that comes out of the nipple area in your breast.
- Breast tenderness
- Decreased sexual interest
- Decreased peripheral vision
- Headache
- Infertility
-
Stopping of menstruation not related to
menopause
, or irregular menstruation
Menopause
Menopause is the time in a woman's life when her periods (menstruation) stop. Most often, it is a natural, normal body change that most often occurs...
- Vision changes
In men:
- Decreased sexual interest
- Decreased peripheral vision
-
Enlargement of breast tissue
(gynecomastia)
Enlargement of breast tissue
When abnormally large breasts develop in males, it is called gynecomastia. It is due to the excess growth of breast tissue, not excess fat tissue....
- Headache
-
Erection problems
(impotence)
Erection problems
An erection problem occurs when a man cannot get or keep an erection that is firm enough for intercourse. You may not be able to get an erection at ...
- Infertility
- Vision changes
Symptoms caused by pressure from a larger tumor may include:
- Headache
-
Lethargy
Lethargy
Fatigue is a feeling of weariness, tiredness, or lack of energy.
- Nasal drainage
- Nausea and vomiting
- Problems with the sense of smell
-
Vision changes, such as double vision,
drooping eyelids
or visual field loss
Drooping eyelids
Ptosis (eyelid drooping) in infants and children is when the upper eyelid is lower than it should be. This may occur in one or both eyes. Eyelid dr...
There may be no symptoms, especially in men.
Exams and Tests
The health care provider will perform a physical exam and ask about your symptoms. You will also be asked about medicines and substances you are taking.
Tests that may be ordered include:
-
Pituitary MRI or
brain CT scan
Brain CT scan
A head computed tomography (CT) scan uses many x-rays to create pictures of the head, including the skull, brain, eye sockets, and sinuses.
-
Testosterone
level in men
Testosterone
A testosterone test measures the amount of the male hormone, testosterone, in the blood. Both men and women produce this hormone. The test described...
-
Prolactin
level
Prolactin
Prolactin is a hormone released by the pituitary gland. The prolactin test measures the amount of prolactin in the blood.
-
Thyroid function
tests
Thyroid function
Thyroid function tests are used to tell whether your thyroid is working normally. The most common thyroid function tests are:Total, or free T4 (the m...
Treatment
Medicine is usually successful in treating prolactinoma. Some people have to take these medicines for life. Some people can stop taking the medicines after a few years, especially if their tumor has disappeared from the MRI. But there is a risk that the tumor may grow and produce prolactin again, especially if it is a large tumor.
A large prolactinoma can sometimes get larger during pregnancy.
Surgery is done in some cases when symptoms are severe, such as a sudden worsening of vision.
Radiation is usually only used in people with prolactinoma that continues to grow or gets worse after both medicine and surgery. It may be given in the form of:
-
Conventional radiation
Conventional radiation
Radiation therapy uses high-powered x-rays, particles, or radioactive seeds to kill cancer cells.
-
Gamma knife or stereotactic radiosurgery
: a type of radiation therapy that focuses high-powered x-rays on a small area in the brain.
Gamma knife or stereotactic radiosurger
Stereotactic radiosurgery (SRS) is a form of radiation therapy that focuses high-power energy on a small area of the body. Despite its name, radiosur...
Outlook (Prognosis)
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.
When to Contact a Medical Professional
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.
References
Glezer A, Bronstein MD. Prolactinomas. Endocrinol Metab Clin North Am . 2015;44:71-78. PMID: 25732643 www.ncbi.nlm.nih.gov/pubmed/25732643 .
Wong A, Eloy JA, Couldwell WT, Liu JK. Update on prolactinomas. Part 1: Clinical manifestations and diagnostic challenges. J Clin Neurosci . 2015;22:1562-1567. PMID: 26256063 www.ncbi.nlm.nih.gov/pubmed/26256063 .
Wong A, Eloy JA, Couldwell WT, Liu JK. Update on prolactinomas. Part 2: Treatment and management strategies. J Clin Neurosci . 2015;22:1568-1574. PMID: 26243714 www.ncbi.nlm.nih.gov/pubmed/26243714 .
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Endocrine glands - illustration
Endocrine glands release hormones (chemical messengers) into the bloodstream to be transported to various organs and tissues throughout the body. For instance, the pancreas secretes insulin, which allows the body to regulate levels of sugar in the blood. The thyroid gets instructions from the pituitary to secrete hormones which determine the pace of chemical activity in the body (the more hormone in the bloodstream, the faster the chemical activity; the less hormone, the slower the activity).
Endocrine glands
illustration
-
Endocrine glands - illustration
Endocrine glands release hormones (chemical messengers) into the bloodstream to be transported to various organs and tissues throughout the body. For instance, the pancreas secretes insulin, which allows the body to regulate levels of sugar in the blood. The thyroid gets instructions from the pituitary to secrete hormones which determine the pace of chemical activity in the body (the more hormone in the bloodstream, the faster the chemical activity; the less hormone, the slower the activity).
Endocrine glands
illustration
Review Date: 10/28/2015
Reviewed By: Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.