Prolactinoma

Prolactinoma is a type of pituitary tumor that affects hormone levels in the body, specifically the hormone prolactin. These tumors are usually noncancerous and occur in the pituitary gland, a small gland at the base of the brain.

The pituitary gland is a pea-sized gland at the base of your brain. It makes several different hormones, including one called prolactin. Prolactin affects the mammary glands and helps women make breast milk. Sometimes, a tumor grows on the pituitary gland and makes too much prolactin. This kind of tumor is called a prolactinoma. It’s the most common type of pituitary tumor and is most often benign, which means it’s not cancer. A new mom’s prolactin levels go up every time their baby nurses. But for men or women who aren’t nursing, high prolactin in the blood can be a sign of a prolactinoma. Doctors don’t know what causes it, but it’s fairly common. It happens more often in women than men, and it’s rare in kids.

Prolactinoma can cause various symptoms and complications if left untreated.

Causes

Prolactinoma is primarily caused by the overproduction of prolactin, a hormone responsible for milk production in women. The exact cause of prolactinoma is not fully understood, but factors such as genetics, hormonal imbalances, and certain medications may contribute to its development.

Prevalence

Prolactinomas are the most common type of pituitary tumor, accounting for about 40% of all pituitary tumors. They can occur at any age but are most commonly diagnosed in women of childbearing age.

Symptoms

The symptoms of prolactinoma can vary between men and women:

Women:

1. Irregular menstrual periods
2. Lack of menstrual periods (amenorrhea)
3. Low sex drive (libido)
4. Painful intercourse due to vaginal dryness
5. Problems with fertility
6. Unusual production of breast milk (galactorrhea)

In premenopausal women, changes in menstrual periods are often noticeable, making prolactinomas more likely to be detected early.

Postmenopausal Women:

Postmenopausal women may not notice symptoms of a small prolactinoma due to the absence of menstrual periods. However, as the tumor grows larger, it may cause symptoms such as:

• vision loss
• changes in vision,
• and headaches as it presses against nearby tissues.

Men:

1. Problems getting or maintaining an erection (erectile dysfunction)
2. Decreased interest in sex (libido)
3. Breast milk production (rare)

In men, prolactinomas tend to be larger at the time of diagnosis. Early signs such as erectile dysfunction or decreased libido may not be recognized as symptoms of a prolactinoma. Headaches or vision problems are often what prompt men to seek medical attention, leading to the diagnosis of a prolactinoma.

Can you gain weight while having Prolactinoma?

Yes, a prolactinoma may indirectly contribute to weight gain, particularly when it is associated with other hormonal imbalances such as hypothyroidism or increased cortisol production. These conditions can disrupt metabolism and lead to weight gain.

Risk Factors

Several factors may increase the risk of developing prolactinoma, including:

• Family history of pituitary tumors
• Certain medications, such as antipsychotic drugs and medications used to treat high blood pressure
• Hormonal imbalances, such as hypothyroidism or polycystic ovary syndrome (PCOS)

Diagnosis

The diagnostic process aims to accurately identify the presence of a prolactinoma, determine its size and extent, assess its impact on hormone levels and pituitary function, and guide treatment decisions accordingly. Here’s what you can expect during the diagnosis:

1. Physical Exam: Your doctor will conduct a physical examination to assess any physical symptoms or signs that may indicate a pituitary tumor.
2. Medical History Questionnaire: You’ll be asked about your medical history, including any symptoms you’re experiencing, your family history of medical conditions, and any medications you’re currently taking.
3. Blood Test: A blood test will be performed to measure the level of prolactin in your blood. High levels of prolactin can indicate the presence of a prolactinoma. Additionally, your thyroid function may also be assessed through blood tests, as abnormalities in thyroid function can sometimes accompany pituitary disorders.
4. MRI (Magnetic Resonance Imaging): If the blood test suggests the presence of a pituitary tumor or if your symptoms warrant further investigation, your doctor may order an MRI scan or computed tomography (CT) scans of your brain. An MRI provides detailed images of the pituitary gland and can help detect the presence and size of a prolactinoma.
5. Additional Tests: If a prolactinoma is confirmed, further blood tests may be conducted to assess the functioning of other hormones produced by the pituitary gland. Additionally, follow-up MRI scans may be scheduled to monitor the tumor’s growth and response to treatment over time.

Treatment

Treatment options for prolactinomas include medication, surgery, and, in rare cases, radiation therapy.

Medication: The primary medications used to treat prolactinomas are bromocriptine (Parlodel) and cabergoline (Dostinex). These drugs are dopamine agonists, meaning they mimic the action of dopamine in the brain, which helps regulate prolactin secretion by the pituitary gland. About 80% of individuals with prolactinomas experience successful tumor shrinkage with these medications. For premenopausal women, normalization of menstrual periods and restoration of fertility are common outcomes with successful medical treatment.

Surgery: Surgical removal of the tumor may be recommended if medication is ineffective or if the individual cannot tolerate medication due to side effects. The surgical approach typically involves transsphenoidal surgery, where the tumor is accessed and removed through the nasal cavity. This procedure can return prolactin levels to normal in about 80% of individuals with small tumors. However, it is less successful (30%-40% success rate) for larger tumors. Transcranial Surgery: Reserved for larger or more extensive tumors, this procedure involves removing the tumor through an opening in the skull.

Radiation Therapy: Radiation therapy is rarely used for prolactinomas and is usually considered when medication and surgery fail to control prolactin levels. This treatment is successful in about one-third of cases.

Treatment decisions are based on factors such as the size and location of the tumor, the individual’s overall health, and their preferences. Regular monitoring is essential to assess treatment response and adjust the treatment plan as needed.

Home Care Tips

In addition to medical treatment, certain lifestyle changes and home care tips may help manage symptoms of prolactinoma, including:

• Maintaining a healthy weight through diet and exercise
• Managing stress levels through relaxation techniques or therapy
• Following up regularly with healthcare providers for monitoring and adjustment of treatment as needed

Prevention

There are no specific measures to prevent prolactinoma, but early detection and treatment can help prevent complications and improve outcomes. Regular medical check-ups and screening for hormonal imbalances may aid in early diagnosis and treatment.

When to See a Doctor

It is essential to consult a healthcare provider if you experience symptoms such as irregular menstrual periods, infertility, or vision problems, as these may indicate underlying hormonal imbalances or pituitary tumors like prolactinoma. Early diagnosis and treatment can help prevent complications and improve prognosis.

Outlook/Prognosis

With proper treatment and management, the outlook for individuals with prolactinoma is generally favorable. Medications, surgery, or radiation therapy can effectively control hormone levels and shrink the tumor, relieving symptoms and improving quality of life. However, regular monitoring and follow-up care are necessary to monitor hormone levels, assess tumor growth, and adjust treatment as needed.

Sources

• Mayo Clinic. (2022). Prolactinoma.
• National Institute of Diabetes and Digestive and Kidney Diseases. (2022). Prolactinoma.
• American Association of Neurological Surgeons. (2022). Prolactinoma.
• Pituitary Society. (2022). Prolactinoma