What does it feel like to have a prolactinoma?
There are two classes of prolactinoma: microprolactinomas, which are less than a half inch
in diameter, and macroprolactinomas, which are larger, and also less common. Men are more
likely to have the larger tumors. Some symptoms are associated with the excess prolactin
and some are caused by the physical bulk of the tumor. The symptoms associated with excess
prolactin are different in women than in men. The symptoms caused by the bulk of the tumor
are common to both sexes, but are more likely to be associated with the larger prolactinomas
(macroprolactinomas).
Effects of excess prolactin in women
Microprolactinomas are more common than macroprolactinomas in women. One of the earliest
symptoms many women notice is loss of periods (amenorrhea). This is caused by the excess
prolactin interfering with the pituitary#s production of the sex hormones FSH and LH, which
control the menstrual cycle, and it may also be associated with loss of sex drive. Lack of
FSH and LH may lead to infertility because of impaired egg release from the ovaries, but
there is effective treatment for this. Women may also develop milk production when not
pregnant (this is called galactorrhea). This is due simply to the biological action of
the excess prolactin and is not a sign of breast cancer. Women with prolactinomas do not
have any increased risk of breast cancer. If excess prolactin is left untreated for a
long time, it can result in loss of bone minerals and osteoporosis.
Effects of excess prolactin in men
Excess prolactin reduces production of the sex hormones FSH and LH by the pituitary.
This can lead to loss of interest in sex and to impotence, and, very rarely, may cause
infertility. Other symptoms that some men may experience include shrinkage of the testes,
decreased beard growth, muscle weakness and breast enlargement. There can also be milk
production (galactorrhea), caused by the prolactin. Please be assured that all the symptoms
can be treated.
Effects of the tumor bulk
Obviously, the larger the tumor, the more likely there will be effects caused by its size.
These effects can include headaches, visual problems, especially loss of peripheral vision
(eg inability to detect people approaching from the side), and less often double vision.
Treatment usually reverses these problems.
