Prolactinomas are the most common hormone-secreting pituitary tumors. Prolactinomas are far less common in children than in adults and constitute less than 2% of supratentorial tumors in children. The average annual incidence of pituitary adenomas in childhood has been estimated to be 0.1 per million children and prolactinomas represent about half of them.
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.