Sometimes, there may be no noticeable signs or symptoms from prolactinoma. When signs and symptoms are present, they may be caused by excessive prolactin in your blood (hyperprolactinemia) or, if the tumor is large, from the pressure of the tumor on surrounding tissues. Because elevated levels of the hormone prolactin cause disruption of the reproductive system (hypogonadism), some of the signs and symptoms of prolactinoma are specific to females or males.
Prolactinoma is one type of tumor that develops in the pituitary gland. The cause of these tumors remains unknown.
The pituitary gland is a small bean-shaped gland situated at the base of your brain. Despite its small size, the pituitary gland influences nearly every part of your body. Its hormones, such as prolactin, help regulate important functions such as growth, blood pressure and reproduction.
Other possible causes of prolactin overproduction include medications, other types of pituitary tumors, an underactive thyroid gland, an injury to the chest, pregnancy and breast-feeding.
Most prolactinomas occur in women between 20 and 50 years old. The disorder is rare in children.
Complications of prolactinoma may include:
- Vision loss. Left untreated, a prolactinoma may grow large enough to compress your optic nerve.
- Hypopituitarism. With larger prolactinomas, pressure on the normal pituitary gland can cause dysfunction of other hormones controlled by the pituitary, resulting in hypothyroidism, adrenal insufficiency and growth hormone deficiency.
- Bone loss (osteoporosis). Too much prolactin can reduce production of the hormones estrogen and testosterone, resulting in decreased bone density and an increased risk of osteoporosis.
Pregnancy complications. During a normal pregnancy, a woman's pituitary gland enlarges and prolactin production increases. A woman who has a large prolactinoma and becomes pregnant may experience additional pituitary growth and associated signs and symptoms, such as headaches and changes in vision.
If you have prolactinoma and you want to become or you already are pregnant, discuss the situation with your doctor because adjustments in your treatment and monitoring may be necessary.