Prolactinoma

Alternative names:

prolactinoma-females

Definition:

A pituitary tumor that causes excess secretion of the hormone prolactin.

Causes, incidence, and risk factors:

Prolactin is a hormone that induces lactation or milk formation. The size of the prolactinoma correlates with the excess prolactin level; the larger the tumor, the higher the level of prolactin that is secreted. Smaller tumors, called microprolactinomas are more common in women, and larger tumors, called macroprolactinomas, are more common in men. Many of the smaller tumors do not appear to progress to larger tumors.

Many women first experience symptoms while on oral contraceptives or have cessation of menses when oral contraceptives are discontinued. Prolactinomas may grow during pregnancy and may be diagnosed in the postpartum period. Sexual dysfunction occurs in many men. Prolactinomas occur most commonly in those under 40 years old. The incidence is 3 out of 10,000 men and 1 out of 1,000 women.