hormonal and metabolic disorders
Prolactinoma
Introduction
Prolactinomas are noncancerous tumors made up from special cells (lactotrophs) in the pituitary gland. The most common symptom of a prolactinoma is galactorrhea, which is the production of breast milk in men or in women other than during and following pregnancy. Prolactinomas cause the overproduction of the hormone prolactin (hyperprolactinemia) by the pituitary gland. Hyperprolactinemia can cause galactorrhea, or unexpected milk production, and infertility in both men and women. The diagnosis is based on measuring the blood levels of the hormone prolactin. Imaging tests may be done to look for a cause. When medication alone does not control prolactin production or shrink the tumor, surgery or sometimes radiation therapy may be done. (See also Overview of the Pituitary Gland .) In both sexes, the most common cause of galactorrhea is a prolactin-secreting tumor (prolactinoma) in the Overview of the Pituitary Gland . Prolactin is a hormone that stimulates the breasts to produce milk. Prolactinomas usually are very small when first diagnosed. They tend to be larger in men than in women, possibly because they may come to attention later. Other tumors just above the pituitary gland that do not produce prolactin can also increase prolactin secretion if they compress the stalk of the pituitary gland. Compressing the stalk can prevent the hormonedopaminefrom reaching the pituitary gland, where it normally acts todecreaseprolactin production. Overproduction of prolactin and the development of galactorrhea may also be induced by medications, including phenothiazines, certain medications given for High Blood Pressure (especially Galactorrhea can occur in both women and men. 