Prolactin-producing adenomas (also called “prolactinomas”) are benign (non-cancerous) tumors of the pituitary gland that produce prolactin and thereby cause higher than normal blood prolactin concentrations. They can cause symptoms, either when the high blood prolactin concentration interferes with the function of the ovaries or testicles or, less commonly, when the adenoma grows large enough to compress nearby structures in the head, such as the nerves to the eyes.
Pathophysiology: Tumor formation is due to neoplastic transformation of anterior pituitary lactotrophs, resulting in excess synthesis and secretion of prolactin (PRL). Linkage to aryl hydrocarbon-interacting protein gene (AIP) mutation has been identified in some families with prolactinoma and in childhood-onset pituitary adenomas.
Symptoms: When prolactin levels get increased there will be no periods, milk production will occur (infrequent in men), loss of axillary and pubic hair and Small gonads, gynecomastia, erectile dysfunction (in males). When there is mass effect then, bitemporal hemianopsia (due to pressure on optic chiasm), vertigo, nausea, vomiting are the symptoms.