What is Prolactinoma? Symptoms, Causes, & Treatment

A prolactinoma is a noncancerous tumor that grows in your pituitary gland and produces too much of a hormone called prolactin. This small, grape-sized gland sits at the base of your brain and normally helps control many body functions.

When you have a prolactinoma, your body makes more prolactin than it needs. This extra hormone can affect your periods, fertility, and milk production, even when you're not pregnant or breastfeeding. The good news is that these tumors are almost always benign and respond well to treatment.

What are the symptoms of prolactinoma?

The symptoms you experience depend on your sex and how much extra prolactin your body is making. Women often notice changes in their menstrual cycles first, while men might experience different effects.

Here are the most common symptoms women experience:

• Irregular periods or periods that stop completely
• Milk leaking from breasts when not pregnant or breastfeeding
• Difficulty getting pregnant
• Decreased interest in sex
• Vaginal dryness during intercourse
• Hot flashes similar to menopause

Men with prolactinomas typically notice these changes:

• Reduced interest in sex or difficulty with erections
• Breast enlargement or tenderness
• Rarely, milk production from the chest
• Infertility or difficulty fathering children
• Loss of body and facial hair
• Fatigue and mood changes

When prolactinomas grow larger, they can press on nearby structures and cause additional symptoms. You might experience headaches, vision problems like seeing double or losing peripheral vision, or even changes in your sense of smell.

Some people also develop bone weakness over time because high prolactin levels can reduce other important hormones that keep bones strong. This happens more gradually and might not cause obvious symptoms until later.

What are the types of prolactinoma?

Doctors classify prolactinomas based on their size, which helps determine the best treatment approach. There are two main types you should know about.

Microprolactinomas are smaller than 10 millimeters across, about the size of a small pea. These represent the majority of prolactinomas, especially in women. They usually cause hormone-related symptoms but rarely grow large enough to press on surrounding brain tissue.

Macroprolactinomas measure 10 millimeters or larger and are more common in men. Because of their size, they're more likely to cause headaches and vision problems in addition to hormone symptoms. They also tend to produce much higher levels of prolactin.

The size of your prolactinoma helps your doctor predict how it might behave and which treatments will work best for your specific situation.

What causes prolactinoma?

The exact reason why prolactinomas develop isn't fully understood, but they appear to result from changes in the cells of your pituitary gland. These changes cause certain cells to grow and multiply more than they should.

Most prolactinomas happen randomly without any clear trigger or family history. Your genes might play a role in some cases, but this is relatively uncommon. Very rarely, prolactinomas can be part of a genetic condition called multiple endocrine neoplasia type 1, which affects several hormone-producing glands.

Certain medications can also raise prolactin levels and sometimes lead to pituitary changes. These include some antidepressants, anti-nausea medications, and drugs used to treat high blood pressure or psychiatric conditions.

It's important to know that prolactinomas are not caused by anything you did or didn't do. They're not related to stress, diet, or lifestyle choices.

When to see a doctor for prolactinoma?

You should schedule an appointment with your doctor if you notice persistent changes in your menstrual cycle, unexpected milk production, or ongoing fertility concerns. These symptoms warrant evaluation even if they seem mild.

For women, missing three or more periods in a row without being pregnant is a clear signal to seek medical attention. Any milk leaking from your breasts when you're not breastfeeding also deserves prompt evaluation.

Men should see their doctor for persistent problems with sexual function, unexplained breast changes, or ongoing fatigue combined with mood changes. These symptoms can have many causes, but they're worth discussing with a healthcare provider.

Seek medical care more urgently if you develop sudden, severe headaches or notice changes in your vision like double vision or loss of peripheral sight. While these symptoms don't always indicate a serious problem, they need prompt evaluation to rule out complications.

What are the risk factors for prolactinoma?

Several factors can influence your likelihood of developing a prolactinoma, though having risk factors doesn't mean you'll definitely develop one. Understanding these factors can help you stay aware of potential symptoms.

Age plays a role, with prolactinomas most commonly diagnosed in people between 20 and 50 years old. Women are more likely to develop microprolactinomas, while men more often have macroprolactinomas when diagnosed.

Your family history might matter in rare cases, particularly if relatives have multiple endocrine neoplasia type 1. However, the vast majority of prolactinomas occur without any family connection.

Taking certain medications long-term can increase your risk. These include some antipsychotic drugs, certain antidepressants, medications for nausea, and some blood pressure medications that affect dopamine in your brain.

Having other pituitary problems or previous radiation to your head and neck area might also slightly increase your risk, though this is uncommon.

What are the possible complications of prolactinoma?

While prolactinomas are generally manageable, leaving them untreated can lead to several long-term health concerns. Understanding these potential complications helps explain why treatment is often recommended.

The most common complications affect your bones and reproductive health. High prolactin levels can reduce estrogen in women and testosterone in men. Over time, this hormonal imbalance can lead to osteoporosis, making your bones more fragile and prone to fractures.

Fertility problems represent another significant concern. Both men and women might struggle to conceive naturally when prolactin levels remain elevated. In women, ovulation can become irregular or stop completely.

For larger prolactinomas, growth-related complications can develop. The tumor might press on nearby structures, potentially affecting your vision permanently or interfering with other pituitary hormones.

Rarely, very large prolactinomas can cause more serious neurological symptoms. These might include persistent headaches, significant vision loss, or problems with other brain functions. However, with proper monitoring and treatment, these severe complications are quite uncommon.

Cardiovascular health can also be affected over time due to hormonal changes, though this typically develops gradually and can often be prevented with appropriate treatment.

How is prolactinoma diagnosed?

Diagnosing a prolactinoma typically starts with a simple blood test to measure your prolactin levels. Your doctor will likely order this test if your symptoms suggest high prolactin.

Normal prolactin levels are usually below 25 nanograms per milliliter in women and below 15 in men. If your levels are elevated, your doctor might repeat the test to confirm the results, since prolactin can fluctuate throughout the day.

Once high prolactin is confirmed, your doctor will likely order an MRI scan of your pituitary gland. This imaging test can show whether a tumor is present and determine its size and exact location.

Your doctor might also test other pituitary hormones to see if the prolactinoma is affecting other gland functions. This comprehensive approach helps create the most effective treatment plan for your specific situation.

Sometimes, additional tests are needed to rule out other causes of high prolactin, such as thyroid problems or kidney disease. Your doctor will guide you through which tests are necessary based on your individual circumstances.

What is the treatment for prolactinoma?

Treatment for prolactinoma usually involves medications that can shrink the tumor and normalize your prolactin levels. Most people respond very well to these treatments and see significant improvement in their symptoms.

The most commonly prescribed medications are called dopamine agonists. These include cabergoline and bromocriptine, which work by mimicking dopamine in your brain. Dopamine naturally suppresses prolactin production, so these medications help restore normal hormone balance.

Cabergoline is often preferred because it's typically taken just twice a week and tends to have fewer side effects. Bromocriptine requires daily dosing but has been used safely for many decades and is often recommended during pregnancy.

Most people notice their symptoms improving within a few weeks to months of starting medication. Prolactin levels often normalize, menstrual periods return, and fertility is restored in many cases.

Surgery is rarely needed but might be considered if medications don't work well or cause intolerable side effects. The most common surgical approach is transsphenoidal surgery, where the surgeon reaches the pituitary gland through your nose.

Radiation therapy is used very rarely, typically only when both medications and surgery haven't been successful. Your medical team will thoroughly discuss all options if standard treatments aren't effective.

How to manage prolactinoma at home?

Taking your medications consistently as prescribed is the most important thing you can do at home. Set up a routine or use reminders to help you remember, especially since some medications are taken only a few times per week.

Keep track of your symptoms in a simple journal or smartphone app. Note changes in your periods, energy levels, or any side effects from medication. This information helps your doctor adjust your treatment if needed.

Focus on maintaining good bone health through regular weight-bearing exercise and adequate calcium and vitamin D intake. Since prolactinomas can affect bone density, these steps become particularly important.

Eat a balanced diet rich in calcium and vitamin D. Good sources include dairy products, leafy green vegetables, and fortified foods. Your doctor might also recommend supplements based on your individual needs.

Manage stress through relaxation techniques, regular exercise, or activities you enjoy. While stress doesn't cause prolactinomas, it can affect your overall well-being and how you cope with treatment.

Stay connected with friends and family for emotional support. Dealing with a hormone-related condition can sometimes affect your mood and relationships, so maintaining good social connections is valuable.

How should you prepare for your doctor appointment?

Before your appointment, write down all your symptoms and when they started. Include details about menstrual changes, any milk production, sexual function concerns, headaches, or vision problems.

Make a complete list of all medications you take, including prescription drugs, over-the-counter medications, and supplements. Some medications can affect prolactin levels, so this information is crucial for your doctor.

Prepare a list of questions you want to ask. You might want to know about treatment options, potential side effects, how long treatment might last, or how the condition could affect your plans for pregnancy.

If possible, bring a family member or friend for support and to help remember important information discussed during the appointment.

Gather any previous test results or medical records related to your symptoms. If you've had blood tests or imaging studies done elsewhere, bring copies or arrange for them to be sent to your doctor's office.

What's the key takeaway about prolactinoma?

Prolactinomas are very treatable conditions that rarely pose serious health risks when properly managed. Most people experience significant improvement in their symptoms with medication and go on to live completely normal lives.

The most important thing to remember is that early diagnosis and treatment can prevent potential complications and restore your quality of life. If you're experiencing symptoms like irregular periods, unexpected milk production, or fertility concerns, don't hesitate to speak with your doctor.

With proper treatment, many people see their prolactin levels return to normal, their symptoms resolve, and their fertility restored. Even larger prolactinomas typically respond well to medication, often shrinking significantly over time.

Stay committed to your treatment plan and maintain regular follow-up appointments with your healthcare team. This ongoing partnership ensures the best possible outcomes and helps catch any changes early.