Prolactinoma is a noncancerous tumor of the pituitary gland. This tumor causes the pituitary to make too much of a hormone called prolactin. The major effect of prolactinoma is decreased levels of some sex hormones — estrogen in women and testosterone in men.

Although prolactinoma isn’t life-threatening, it can cause vision difficulties, infertility and other problems. Prolactinoma is the most common type of hormone-producing tumor that can develop in your pituitary gland. Doctors can often treat prolactinoma with medications to restore your prolactin level to normal. Surgery to remove the pituitary tumor also might be an option.