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  • Prolactinoma

    Prolactinomas are benign tumors of the pituitary gland resulting in the overproduction of the prolactin hormone.

    These growths represent the most common form of neoplasia in the pituitary gland and affect as much as 8% of the U.S population (according to some autopsy studies). Although these growths are benign, they can lead to irreversible defects of the reproductive system and the overproduction of breast milk in women.

    No one knows what causes pituitary tumors, but studies have indicated that stress can significantly increase prolactin levels. It should be noted that these studies merely suggest that stress is a key factor in pituitary neoplasia. There is no evidence that prolactinomas are genetically passed from a parent to offspring; thus, they are considered to be a sporadic tumor.

    Common Signs and Symptoms

    Women can more easily identify a potential pituitary tumors than men because such growths usually disrupt menstruation. Men, on the other hand, are rarely given dependable indicators of a prolactinoma until the onset of far more serious complications. Men and women are both affected with hyperprolactinaemia as a result of prolactinomas.

    This disorder is characterized by the overproduction of the prolactin hormone which can lead to irregular menstruation in women, hypogonadism (this term is usually applied to permanent defects of the ovaries or testes), erectile disfunction (ED) in men, and infertility or sterility. Particularly large prolactinomas or macroprolactinomas can press against various structures that surround the pituitary gland which usually leads to headaches and/or the loss of vision.


    Diagnosis of a prolactinoma is dependent on the detection of high prolactin levels in the blood. A doctor has reason to test for high prolactin levels if a patient is experiencing infertility, disruption of the menstrual cycle, and/or galactorrhea (milk secretion). If prolactin levels are high, a physician will then typically request a magnetic resonance imaging (MRI) to accurately detect the presence and size of the pituitary tumor. A less sensitive alternative to the MRI is Computed Tomography or the CT Scan. If the tumor is large and/or has caused damage to surrounding, a doctor may request an eye exam.


    Treating a prolactinoma usually incorporates some or all of the following goals, all of which are intended to restore the pituitary gland and any other damaged structures and/or processes of the body to a state of normal functionality: Return prolactin secretion to normal, reduce the size of the tumor and/or remove the tumor completely, and correct any vision anomalies.

    Exercise is an important part of prolactinoma treatment as well because it reduces stress levels which stimulate the production of prolactin. Furthermore, abnormal prolactin levels can contribute to the proliferation of an existing prolactinoma and/or the development of new prolactinomas and, thus, recognizing and reducing stress is the best preventative treatment available.

    Many drugs are available to treat the overproduction of prolactin and the various effects therein. Dopamine and dopamine agonist (drugs that act like dopamine such as bromocriptine and cabergoline) reduce tumor size and reverse the overproduction of prolactin in 80% of patients.

    Treatment is often started slowly with dopamine agonists to avoid nausea and dizziness. It is also important for the patient to continue the treatment until a qualified endocrinologist advises otherwise. Prolactin levels typically rise when dopamine agonist treatment is discontinued.

    Surgery is utilized if drug treatment is ineffective and/or if the tumor is pressing aggressively against surrounding structures. Removing a pituitary tumor requires the hand of a very skilled neurosurgeon and, thus, patients should ask the surgeon about their past experience with pituitary tumor removal.

    They should clarify how many many pituitary tumor operations they have completed and about the success and complication rates of those procedures as compared to the results of other major medical centers. It is worth a patient’s efforts in time and money to locate a physician that has performed hundreds or even thousands of pituitary tumor removals. Even with experienced physicians, it should be noted that 20 to 50% of all prolactinomas will recur, typically within five years.


    95% of all small prolactinomas or microprolactinomas will not grow after a four to six year period and, thus, affect the body with much less serious symptoms than macroprolactinomas. Macroprolactinomas typically require regular monitoring by a qualified specialist, drug therapy, and/or surgery.