Prolactinoma

From: www.nlm.nih.gov

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

Causes
Prolactin is a hormone that triggers lactation or milk production.
Prolactinoma is the most common type of noncancerous pituitary tumor (adenoma), making up at least 30% of all pituitary adenomas.
Prolactinomas occur most commonly in people under age 40. They are about five times more common in women than men, but are rare in children.
At least half of all prolactinomas are very small (less than 1 cm or 3/8ths of an inch in diameter). These microprolactinomas are more common in women. Many small tumors remain small and never get larger.
Larger tumors, called macroprolactinomas, are more common in men. Prolactinomas in men tend to occur at an older age and can grow to a large size before any symptoms appear.

Symptoms
In women:
Abnormal milk flow from the breast in a woman who is not pregnant or nursing (galactorrhea)
Breast tenderness
Stopping of menstruation not related to menopause
Decreased sexual interest
Headache
Infertility
Vision changes
In men:
Decreased sexual interest
Enlargement of breast tissue (gynecomastia)
Headache
Impotence
Infertility
Vision changes
Note: There may be no symptoms, particularly in men.

Exams and Tests
Cranial MRI or cranial CT scan showing a pituitary mass
Decreased testosterone levels in men
Prolactin levels

Treatment
Not everyone needs treatment for prolactinoma.
Medication is usually successful in treating prolactinoma. Surgery is done in some cases where the tumor may damage vision.
In women, treatment can improve:
Infertility
Irregular menstruation
Loss of sexual interest
Milk flow not related to childbirth or nursing
Men should be treated when they have:
Decreased sexual drive
Impotence
Infertility
Large prolactinomas generally must be treated to prevent vision loss.

Bromocriptine and cabergoline are drugs that reduce prolactin levels in both men and women. They usually must be taken for life. If the drug is stopped, the tumor may grow and produce prolactin again, especially if it is a large tumor. Most people respond well to these drugs, although large prolactinomas are more difficult to treat. Both drugs may cause dizziness and upset stomach.

Using bromocriptine over time can reduce the chance of being cured by removing the tumor. Therefore, if surgery is needed, it is best to remove the tumor during the first 6 months of using this drug.

Radiotherapy with conventional radiation or gamma knife is usually reserved for patients with prolactinoma that continues or gets worse after both medication and surgery.

Outlook (Prognosis)
The outlook depends greatly on the success of medical therapy or surgery. Tests to check for recurrence of the tumor following treatment are important.

Possible Complications
Bleeding
Tumor regrowth
If untreated, a growing tumor can press on the optic nerves and cause:
Blindness
Double vision
Permanent vision loss
When to Contact a Medical Professional
See your health care provider if you have any symptoms of prolactinoma.

If you have had a prolactinoma in the past, call your health care provider if the symptoms return.

Alternative Names
Prolactinoma - females; Adenoma - secreting; Prolactin-secreting adenoma of the pituitary

References
Melmed S, Kleinberg D. Anterior pituitary. In: Kronenberg HM, Melmed S, Polonsky KS, Larsen PR, eds. Williams Textbook of Endocrinology. Philadelphia, PA: Saunders Elsevier; 2008:chap 8.

Update Date: 6/20/2008
Updated by: A.D.A.M. Editorial Team: David Zieve, MD, MHA, Greg Juhn, MTPW, David R. Eltz. Elizabeth H. Holt, MD, PhD, Assistant Professor of Medicine, Section of Endocrinology and Metabolism, Yale University. Review provided by VeriMed Healthcare Network (3/18/2008).

From: www.uptodate.com

RECOMMENDATIONS — Based upon the treatments now available, we make the following recommendations:

For patients with lactotroph microadenomas and any degree of hypogonadism we recommend initial treatment with a dopamine agonist (Grade 1B) (see "Microadenomas" above)

We recommend cabergoline as the initial choice of dopamine agonists in most circumstances, because it is most likely to be effective and least likely to cause side effects (Grade 1B) (see "Dopamine agonists" above)

Because of a possible association between high dose cabergoline use (for Parkinson disease) and valvular heart disease, we suggest using the lowest dose of cabergoline necessary to lower prolactin to normal and to attempt a trial of withdrawal if the prolactin concentration and the size of the pituitary have been normal for two or more years. (See "Valvular heart disease" above and see "Withdrawal of therapy" above).

If the patient cannot tolerate the first dopamine agonist administered, or serum prolactin concentrations do not normalize, we suggest switching to a second dopamine agonist (Grade 2C) (see "Dopamine agonists" above) Starting doses and upward titration of dose based upon clinical response are reviewed above (see "Microadenomas" above).

In women with lactotroph microadenomas seeking fertility whose serum prolactin concentrations do not normalize with dopamine agonist therapy (and therefore do not ovulate), we suggest ovulation induction with clomiphene citrate or gonadotropin therapy (Grade 2B) (See "Overview of ovulation induction")

For patients with lactotroph macroadenomas, no matter how large or how severe the neurologic sequelae, we recommend initial treatment with a dopamine agonist (Grade 1B). Dosing is the same as that for microadenomas (see "Microadenomas" above).

We suggest transsphenoidal surgery when dopamine agonist treatment has been unsuccessful in lowering the serum prolactin concentration or size of the macroadenoma and symptoms or signs due to hyperprolactinemia or adenoma size persist during treatment (Grade 1B) (see "Transsphenoidal surgery" above)

We also suggest transsphenoidal surgery in women with giant lactotroph adenomas, (>3 cm), who wish to become pregnant, even if the adenoma responds to a dopamine agonist (Grade 2C). The rationale for this approach is that if such a patient becomes pregnant and discontinues the agonist for the duration of pregnancy, the adenoma may increase to a clinically important size before delivery (see "Transsphenoidal surgery" above).

In patients with large macroadenomas who have undergone transsphenoidal debulking, we suggest radiation therapy to prevent regrowth of residual tumor (Grade 2C). We recommend not using radiation therapy for the primary treatment of patients with macroadenomas or at all for those with microadenomas (Grade 1B) (see "Radiation therapy" above).

In premenopausal women who have lactotroph microadenomas causing hyperprolactinemia and hypogonadism but who cannot tolerate or do not respond to dopamine agonists and do not want to become pregnant, we suggest postmenopausal hormone therapy to prevent bone loss (Grade 2B) (see "Estrogen" above)

We also suggest gonadal steroid replacement therapy in patients with hyperprolactinemia and hypogonadism due to antipsychotic agents (estradiol-progestin in women and testosterone in men) (Grade 2C) (see "Drug use" above)