Hyperpituitarism is a condition caused by overactivity of the anterior lobe of the pituitary gland resulting in secretion of prolactin. Lactation occurs in men and non-breastfeeding women.

Most conditions are caused by small tumors (microadenomas less than 10mm in diameter). These tumors, also called prolactinomas, are the most common secreting tumors of the pituitary. Primary hypothyroidism can also cause high prolactin levels in the blood (prolactinemia). Certain drugs may also cause high prolactin levels, e.g., phenothiazines, butyrophenomas, tricyclic antidepressants, etc. Breast stimulation, and trauma or disease involving the chest wall can cause increases in prolactin levels. Elevated prolactin levels are normal following pregnancy up to six months after delivery, or after breast-feeding is stopped.

Loss of menses occurs in women, as well as estrogen-deficiency symptoms of painful intercourse and hot flashes. Men have loss of libido and potency, galactorrhea, complaints of visual disturbances and headache.

Base-line prolactin levels are obtained. Lack of elevated thyroid-stimulating hormone may rule out the thyroid gland as the primary cause. A computed tomography (CT) scan or magnetic resonance imaging (MRI) is used to determine the size of the adenomas. Inability to visualize the adenoma does not rule out its presence. Its presence is assumed by virtue of the elevated levels of prolactin. These tumors are called microadenomas. Patients with adenomas 10mm in diameter (macroadenomas) whether they desire treatment for the condition or not, should have visual field examinations done periodically.

The method of treating the tumors is controversial. Those persons with normal CT or MRI scans, prolactin levels below 100 ng/mL, and microadenomas can be watched or treated with certain prescription drugs. Treatment depends on the size of the tumor and the symptoms it is causing. A small non-enlarging tumor in a female with insignificant galactorrhea who does not desire pregnancy need not be treated. However, if pregnancy is desired, or symptoms are either intolerable or the tumor is enlarging, then treatment is indicated. All patients should have monitoring of prolactin levels quarterly, and radiology studies at least annually. After thorough testing, patients with macroadenomas should be treated with medication or surgery.

Patients should be monitored and evaluated for the remainder of their lives. Use of radiotherapy as a treatment for patients who do not respond to other methods usually results in hypopituitarism several years later.

• Consider service connection on a presumptive basis as a chronic condition (38 CFR §3.307; §3.309 (a)).

• Note: Evaluate as malignant or benign neoplasm, as appropriate.