Prolactinome

A prolactinoma is a tumor (adenoma) of the pituitary gland that produces the hormone prolactin. It is the most common type of functioning pituitary tumor. Symptoms of prolactinoma are due to abnormally high levels of prolactin in the blood (hyperprolactinemia), or due to pressure of the tumor on surrounding tissues. Based on size, a prolactinoma can be classified as a microprolactinoma (10 mm diameter). Hyperprolactinaemia The symptoms due to a prolactinoma are broadly divided into those that are caused by increased prolactin levels or mass effect. Those that are caused by increased prolactin levels are: Amenorrhea (disappearance of ovulation periods) Galactorrhea (Milk production; infrequent in men) Loss of axillary and pubic hair Hypogonadism (Reduced function of the gonads.) Gynecomastia (an increase in male breast size) Erectile dysfunction (in males) Those that are caused by mass effect are: Headaches Vision Changes-visual field deficits, blurred vision, decreased visual acuity Cranial nerve palsies-especially with invasive tumors or with pituitary apoplexy Seizures, Hydrocephalus, Unilateral exophthalmos are rare presentations Hypopituitarism Pituitary apoplexy is a medical emergency because of spontaneous hemorrhage into the pituitary tumor and presents with severe headaches, vision changes, and acute panhypopituitarism. The cause of pituitary tumors remains unknown. Though most pituitary tumors are sporadic, some genetic syndromes include increased risk for pituitary adenomas including Multiple endocrine neoplasia type 1 (caused by a mutation in the MEN1 gene) and Familial isolated pituitary adenoma (FIPA). The majority of moderately raised prolactin levels (up to 5000 mIU/L) are not due to microprolactinomas but other causes. The effects of some prescription drugs are the most common. Other causes are other pituitary tumours and normal pregnancy and breastfeeding. This is discussed more under hyperprolactinaemia.