Prolactinoma Overview

A prolactinoma is a benign tumor (adenoma) of the pituitary gland, a pea-sized structure at the base of the brain. Known as the “master gland,” the pituitary gland produces hormones that control many vital bodily functions. Prolactinoma causes the pituitary gland to produce too much prolactin, a hormone responsible for breast tissue development, milk production, and lactation. The tumors can vary in size and typically originate in the front part of the pituitary gland (anterior pituitary).

Prolactinoma is the most common type of pituitary tumor, accounting for approximately 40% of pituitary adenomas. The condition is more common in females than males, and most cases are diagnosed between adolescence and age 40.

Prolactinoma Causes and Risk Factors

Based on the research performed to date, scientists believe prolactinoma most likely arises due to a yet-undetermined combination of genetic, hormonal, and/or environmental factors. In some cases, the condition occurs without a genetic link (sporadically).

One possible cause of sporadic prolactinoma is an overgrowth of prolactin-producing cells in the pituitary gland, leading to the formation of a tumor. Although stress, pregnancy, and breastfeeding can temporarily increase prolactin levels, these factors are not confirmed to be direct causes of prolactinoma. However, hormonal imbalances, such as increased estrogen and decreased dopamine (a neurotransmitter that inhibits prolactin production), may contribute to the development of prolactinoma.

Certain antipsychotic drugs can increase the risk of prolactinoma by disrupting dopamine levels in the brain. Additionally, an inherited condition known as multiple endocrine neoplasia (MEN) type 1 is a known risk factor.

Prolactinoma Signs and Symptoms

A prolactinoma may not cause noticeable warning signs, especially if it is small. However, symptoms may develop if the tumor presses on surrounding tissues or increases the level of prolactin in the bloodstream (hyperprolactinemia). The symptoms can vary depending on the size and behavior of the tumor. In some cases, prolactinoma causes infertility.

What Does a Prolactinoma Feel Like?

Prolactinoma symptoms that can be felt include:

  • Decreased libido
  • Erectile dysfunction in men
  • Vaginal dryness in women that causes pain during sexual intercourse
  • Headaches
  • Weakened bones and frequent fractures

What Does a Prolactinoma Look Like?

Prolactinoma symptoms that can be seen include:

  • Breast enlargement (gynecomastia) in men
  • Muscle atrophy in men
  • Milk production (galactorrhea) in nonpregnant women
  • Acne and excessive facial and body hair growth in women
  • Vision problems

Prolactinoma Diagnosis

Prolactinoma is typically diagnosed through a combination of medical history, physical examination, vision testing, and blood work to measure the levels of prolactin and other pituitary hormones in the bloodstream. If a physician suspects prolactinoma based on the symptoms or diagnostic test results, they may order imaging, such as a magnetic resonance imaging (MRI) scan of the brain to visualize the pituitary gland and confirm the presence of a tumor. The physician may also refer the patient to an endocrinologist for further evaluation.

Prolactinoma Treatment

Medication is the primary treatment for prolactinoma. Dopamine agonists such as cabergoline and bromocriptine can control the level of prolactin in the blood and shrink the tumor.

If medication-based treatment is ineffective, other options may include surgery and radiation therapy. Transsphenoidal surgery, the most common surgical approach, involves removing the pituitary tumor through an incision at the back of the nasal cavity or under the upper lip. Transcranial surgery may be considered to remove a large tumor through an opening in the skull.

Benefit From World-Class Care at TGH

Tampa General Hospital ranks among the top 10% of hospitals in the nation for Neurology & Neurosurgery as recognized by U.S. News & World Report for 2023-24. Housed within our acclaimed Neuroscience Institute, TGH’s Pituitary Tumor Center offers world-class care for the management and treatment of pituitary tumors and related hormonal imbalances.

If you would like to learn more about prolactinoma, you can request a consultation with a specialist in Tampa, FL, by calling (800) 822-3627 today.