Prolactinoma -What are the symptoms of a prolactinoma?

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Prolactinomas come to attention because of the effect of the elevated prolactin on the reproductive system and/or the size of the tumor. A very large tumor may cause pressure on the optic nerves or nearby brain tissue leading to headaches and/or vision problems.

Symptoms in Women

High levels of prolactin made by the tumor interfere with the ability of the ovaries to make estrogen. When estrogen levels are low, women will have absent or irregular menstrual periods, low sex drive, vaginal dryness and difficulty achieving a pregnancy. Because of the effect of elevated prolactin levels on breast tissue, women who are not pregnant or breastfeeding frequently experience a milky breast discharge. This condition is called GALACTORRHEA.

Table 1. Most Common Presenting Symptoms



Absent or irregular periods

Headaches/vision problems


Low sex drive

Low sex drive

Erectile dysfunction

Vaginal dryness

Infertility (rare)

Difficulty achieving pregnancy

Galactorrhea (rare)


Women with prolactinomas will rarely have headaches, visual symptoms or other complaints related to tumor size because most prolactinomas in women are small and often do not progressively increase in size.

Symptoms in Men

Even slight elevations in prolactin levels from very small pituitary tumors can lead to a decrease in sex drive and cause erectile dysfunction. Larger tumors in men are associated with very high levels of prolactin which almost always cause sexual dysfunction. Breast discharge (galactorrhea) can occur in men, but is much less common than in women.

Men with prolactinomas may also seek medical attention because of headaches or vision problems due to large tumors which can cause pressure on the optic nerves. Because of the size of these tumors, prolactin levels are often very high. The high levels of prolactin can limit the ability of the testes to make testosterone and can infrequently cause infertility.

Because of the low estrogen and testosterone levels that may occur with elevated prolactin, some men and women also develop low bone density; however, fractures and osteoporosis are uncommon.

Since prolactin inhibits the ability of the testes to produce testosterone, men with prolactinomas often present to their doctor with decreased sex drive and/or erectile dysfunction.