Dr. M.J. Bazos, MD.
Patient Handout
PROLACTINOMA
About Your
DiagnosisA prolactinoma is a tumor of
the prolactin-producing cells of the pituitary gland. The pituitary gland, or
master gland, sits at the base of the brain and regulates normal growth,
metabolism, and reproduction. One of the many hormones secreted by the pituitary
is prolactin. Prolactin is the hormone that causes a woman’s breasts to
secrete milk after pregnancy. If a tumor develops in the prolactin-secreting
cells of the pituitary, too much prolactin is secreted into the bloodstream. One
or two individuals in 10,000 will have
aprolactinoma. There is no known genetic
link for this disorder. A prolactinoma is detected by measuring prolactin levels
in the blood. It is important that patients are not taking certain medicines
such as reserpine, alpha-methyldopa, metoclopramide, haloperidol, or
trifluoperazine because prolactin levels could be falsely elevated. Prolactin
levels may also be falsely elevated in patients with hypothyroidism or advanced
kidney disease. The diagnosis is confirmed by obtaining a magnetic resonance
imaging (MRI) scan of the pituitary gland. Most prolactinomas are completely
curable with medication or
surgery.Living With Your
DiagnosisWomen may have changes in
their menses, or have milk production when they are not pregnant. Elevated
prolactin levels may decrease estrogen levels, leading to vaginal dryness and
painful intercourse. Males may only notice impotence or decreased sex drive.
Untreated prolactinoma could lead to decreased bone mineral density or
osteoporosis. It may also compress local nerves near the pituitary such as the
optic nerves, which are important for vision. This causes a decrease in
peripheral
vision.TreatmentThe
best treatment for a prolactinoma depends on the extent of the patient’s
symptoms as well as the extent of the tumor. The goal of treatment is to restore
normal reproductive and pituitary function, as well as to minimize symptoms such
as breast milky discharge and change in menstrual periods. Some patients with
microadenomas of less than 10 mm who have no symptoms of their disease may be
followed up clinically with annual MRI scans of the pituitary and annual
prolactin levels. The vast majority of prolactinomas of this size do not
progress to larger tumors. Medication is required for symptomatic patients.
Bromocriptine increases dopamine secretion from the hypothalamus, which leads to
decreased prolactin levels and tumor shrinkage in most patients. Bromocriptine,
1.25 mg, is taken once at night with food for several days; the dose is then
slowly increased until prolactin levels are normal or side effects, such as
nausea or dizziness, become intolerable. Cabergoline is a newer longer-acting
medication which may be better tolerated than bromocriptine. If medical therapy
is not tolerated or fails to control the growth of the prolactinoma, then
surgery is required. This also has a very high success rate if the prolactinoma
is identified early. Tumors may recur postoperatively. Complications of surgery
include bleeding, infection, leaking cerebrospinal fluid (CSF), and
hypopituitarism (an underactive pituitary) requiring hormone
replacement.The
DOs• Make sure your prolactin
level was measured while you were fasting for at least 8 hours, and that there
has not been recent breast
stimulation.• Obtain follow-up
images of the pituitary to prove the prolactinoma is not
growing.• Start with a low dose of
medication and increase the dose
slowly.• Find an experienced
neurosurgeon if you require surgery for your prolactinoma. Success rates are
highly dependent upon the experience and skill of the
neurosurgeon.The
DON’Ts• Don’t give
up on your medicine if you are having mild side effects. Instead, decrease your
dose by one pill a day, and increase again 1 week
later.• Don’t forget to use
appropriate birth control if you are sexually active after beginning treatment
for your prolactinoma. Women with irregular menstrual periods or men with low
testosterone levels will have normalization of their reproductive status with
treatment of their prolactinoma.When to
Call Your Doctor• You experience
any change in your vision.• You have
an unusual increase in headaches.•
You have nausea or dizziness as a result of the
medicine.• You are feeling
excessively weak and tired or are urinating frequently after prolactinoma
surgery.Websites:The
National Institute of Diabetes and Digestive and Kidney Diseaseshttp://www.niddk.nih.gov/prolactinoma