Prolactinoma
Adenoma - secreting; Prolactin - secreting adenoma of the pituitaryA 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) 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).
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...
Read Article Now Book Mark ArticleMultiple 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...
Read Article Now Book Mark ArticleProlactinomas occur most commonly in people under age 40. They are more common in women than in men and are rare in children.
At least half of all prolactinomas are very small (less than 3/8 of an inch or 1 centimeter [cm] 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 young women than in men because the high prolactin causes irregular menstrual periods.
Symptoms
In women:
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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.
Read Article Now Book Mark Article - Breast tenderness
- Decreased sexual interest (libido)
- Decreased peripheral vision
- Headache
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Infertility
Infertility
Infertility means you cannot get pregnant (conceive). There are 2 types of infertility:Primary infertility refers to couples who have not become preg...
Read Article Now Book Mark Article - 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 occurs between ag...
Read Article Now Book Mark Article - Vision changes
In men:
- Decreased sexual interest (libido)
- Decreased peripheral vision
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Enlargement of breast tissue (gynecomastia)
Enlargement of breast tissue
When abnormal breast tissue develops in males, it is called gynecomastia. It is important to find out if the excess growth is breast tissue and not ...
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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 ...
Read Article Now Book Mark Article - Infertility
- Vision changes
Symptoms caused by pressure from a larger tumor may include:
- Headache
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Lethargy
Lethargy
Fatigue is a feeling of weariness, tiredness, or lack of energy.
Read Article Now Book Mark Article - 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
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...
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There may be no symptoms, especially in older men.
Exams and Tests
Your 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.
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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...
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Prolactin level
Prolactin
Prolactin is a hormone released by the pituitary gland. The prolactin test measures the amount of prolactin in the blood.
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Thyroid function tests (important because an underactive thyroid can mimic a prolactinoma - pseudoprolactinoma)
Thyroid function
Thyroid function tests are used to check whether your thyroid is working normally. The most common thyroid function tests are:Free T4 (free thyroxine...
Read Article Now Book Mark Article - Other tests of pituitary function
Treatment
Medicine is usually successful in treating prolactinoma. Some people have to take these medicines for life. Other people can stop taking the medicines after 2 to 3 years, especially if their tumor was small (less than 1 cm) when it was discovered or has disappeared from the MRI images. 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 a prolactinoma that continues to grow or gets worse after both medicine and surgery have been tried. Radiation may be given in the form of:
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Conventional radiation
Conventional radiation
Radiation therapy uses high-powered radiation (such as x-rays or gamma rays), particles, or radioactive seeds to kill cancer cells.
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Gamma knife (stereotactic radiosurgery) -- a type of radiation therapy that focuses high-powered x-rays on a small area in the brain.
Gamma knife (stereotactic radiosurgery)
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...
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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 with a higher than usual estrogen content.
Untreated pituitary adenomas always have a small risk of suddenly getting bigger, most commonly from bleeding inside the tumor. This is called pituitary apoplexy, and it is a medical emergency. Most people with pituitary apoplexy describe it as having the worst headache of their life.
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, contact your provider for a general follow-up, or if your symptoms return.
References
Bronstein MD, Glezer A. Prolactinomas and disorders of prolactin secretion. In: Robertson RP, ed. DeGroot's Endocrinology. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 35.
Cooper PE, Van Uum SHM. Neuroendocrinology. In: Jankovic J, Mazziotta JC, Pomeroy SL, Newman NJ, eds. Bradley and Daroff's Neurology in Clinical Practice. 8th ed. Philadelphia, PA: Elsevier; 2022:chap 50.
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/.
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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 rate of metabolism in the body (the more hormone in the bloodstream, the faster the chemical activity; the less hormone, the slower the activity).
Endocrine glands
illustration
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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 rate of metabolism 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: 5/12/2023
Reviewed By: Sandeep K. Dhaliwal, MD, board-certified in Diabetes, Endocrinology, and Metabolism, Springfield, VA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.