Many people first learn they have a prolactinoma unexpectedly, either from an MRI ordered for another reason or from blood work that comes back with unexpectedly high prolactin levels. If that is you, start with the reassuring part. A prolactinoma is the most common type of pituitary tumor, it is almost always benign, and most cases are very manageable with medication. This page explains what a prolactinoma is, the symptoms it can cause in women and men, and how PACT Endocrinology diagnoses and treats it.
A prolactinoma is a benign, or noncancerous, tumor of the pituitary gland, the pea-sized gland at the base of the brain that directs much of the body’s hormone production. The tumor makes too much prolactin, the hormone best known for stimulating breast milk during pregnancy and breastfeeding. Outside those times, prolactin normally stays low, so when it runs high, it can quietly disrupt other hormones, which is often what brings the first symptoms to light. In other words, the trouble is rarely the tumor itself and more often the extra hormone it produces.
Prolactinomas are the most common type of pituitary tumor, accounting for about 40 percent of all pituitary tumors. They affect both women and men, though they are found more often in women. Size matters here. Most are small, under 10 mm across, and are called microadenomas. These smaller tumors rarely cause structural problems and respond well to treatment. Larger tumors, called macroadenomas, are less common but can press on nearby structures, which is why early evaluation is worthwhile. Doctors call the state of having too much prolactin in the blood hyperprolactinemia, and a prolactinoma is the most common tumor behind it. These tumors are uncommon in children and teenagers and are usually diagnosed in adulthood.
Because prolactin influences reproductive hormones, the symptoms of high prolactin levels often differ between women and men, and many are subtle enough to be mistaken for something else. Women tend to notice changes earlier, since irregular periods or unexpected breast milk are hard to ignore. In men, the signs can be easier to overlook, so a prolactinoma may not be found until it is larger.
In women, elevated prolactin often shows up as:
In men, high prolactin can cause:
Larger tumors can cause symptoms from their size alone by pressing on nearby structures:
Vision changes tend to appear only with larger tumors, which are the exception rather than the rule. Most prolactinomas are found while still small, well before they reach that point.
Diagnosis usually starts with a simple blood test that measures the level of prolactin in your blood. A high result does not automatically mean a tumor, since prolactin can also rise from pregnancy, certain medications, an underactive thyroid, or even a stressful blood draw. Your doctor will rule out these other causes first. When prolactin is genuinely elevated, the next steps typically include:
A mildly high reading is often rechecked before any imaging, since a single value can be misleading. Once a prolactinoma is confirmed, its size and its effect on nearby structures guide what comes next. An endocrinologist coordinates this evaluation and interprets the results together because getting the cause right is what points you toward the simplest effective treatment.
The encouraging headline is that most prolactinomas are treated successfully without surgery. Treatment is matched to the size of the tumor, your symptoms, and how your body responds.
Dopamine agonists, such as cabergoline or bromocriptine, are the first choice, and they are highly effective. They lower prolactin levels and shrink the tumor in about four out of five patients with small tumors. Many people see their periods, fertility, or testosterone return to normal, and after a stable stretch, some can taper off the medication under their physician’s supervision. Cabergoline is often the preferred option, since it works well and is usually taken only once or twice a week. For women hoping to conceive, these medicines are also very effective at restoring fertility. Either way, follow-up includes periodic prolactin checks and repeat imaging to confirm the tumor is stable or shrinking.
Surgery is considered when medication is not tolerated or does not work, or for very large tumors that threaten vision. The standard approach is transsphenoidal surgery, done through the nasal passages, which avoids any external incision.
Note: Most patients with microadenomas do very well over the long term and lead completely normal lives with the right management.
PACT Endocrinology evaluates and manages prolactinoma along with other pituitary and hormone disorders. If your labs have shown elevated prolactin, our team can find the cause and guide your next step.
Not in the way most people fear. A prolactinoma grows in the pituitary gland at the base of the brain, but it is benign and is not brain cancer. Care focuses on controlling the extra prolactin, not removing a dangerous growth.
Yes. High prolactin can disrupt ovulation and lower testosterone, a common reason couples struggle to conceive. Treatment usually restores fertility, and many people go on to have healthy pregnancies. Tell your doctor if you are planning to conceive, since your medication may change.
Not always. If prolactin stays normal and the tumor is no longer visible after a couple of years, the medication can sometimes be reduced and stopped under a doctor’s supervision. Levels can rise again afterward, so monitoring continues.
Untreated high prolactin can keep sex hormones low, which may lead to ongoing infertility and, over time, bone thinning. A larger tumor can also grow and press on the nerves that affect vision. Most of this is preventable, so an evaluation is worthwhile.
No diet or supplement reliably shrinks a prolactinoma, since the high prolactin comes from the tumor and responds to medication. Managing stress and sleep and reviewing any medications that raise prolactin with your doctor can help, but they are not a substitute for treatment.
PACT, LLC & PACT MSO, LLC
322 East Main Street, Suite 1B
Branford, CT 06405
PACT, LLC & PACT MSO, LLC
322 East Main Street, Suite 1B
Branford, CT 06405
