Which hormone is elevated in prolactinomas?

Prolactinomas are a type of pituitary adenoma characterized by the excessive production of prolactin, a hormone responsible for lactation as well as other functions in the body. In these tumors, the pituitary gland secretes higher than normal levels of prolactin due to the hyperplastic pituitary tissue.

The elevated prolactin levels can lead to a variety of clinical symptoms, such as galactorrhea (milk production not associated with childbirth), amenorrhea (absence of menstruation), and infertility. Monitoring prolactin levels is crucial in diagnosing and managing prolactinomas, as the hormone's levels directly correlate with the tumor's activity and size.

Other hormones such as growth hormone, IGF-1, and cortisol are not primarily linked to prolactinomas. Growth hormone increases are typically seen in other types of pituitary tumors, IGF-1 levels relate to growth hormone activity, and cortisol elevation is associated with Cushing's syndrome. Thus, the definitive marker for prolactinomas is the elevated level of prolactin itself, confirming the hormonal pathology associated with these tumors.