PANCE Blueprint Endocrinology (7%)

Prolactinoma is a prolactin secreting tumor of the pituitary gland. This tumor is the most common adenoma of the pituitary gland. These tumors are benign but can cause symptoms due to elevated prolactin levels in the blood or by compression of nearby structures. Prolactin is the hormone that stimulates the breast to produce breast milk. Therefore, elevated prolactin levels are usually seen during pregnancy and after childbirth. Pathologic secretion of prolactin from prolactinomas can cause galactorrhea in women although rare in men because of insufficient breast tissue. Prolactin also inhibits the release of gonadotropin releasing hormone. Normally, GnRH stimulates the release of FSH and LH from the anterior pituitary, which plays an important role in the synthesis of sex hormones. Increased prolactin can therefore cause decreased levels of sex hormone in men and women, leading to impotence and amenorrhea, respectively. Enlargement of the tumor can lead to compression of the optic chiasm resulting in bitemporal hemianopia. Dopamine physiologically suppresses prolactin secretion and is used in the treatment of prolactinomas.