What is (are) Prolactinoma ?
A prolactinoma is a benign noncancerous tumor of the pituitary gland that produces a hormone called prolactin. Prolactinomas are the most common type of pituitary tumor. Symptoms of prolactinoma are caused by hyperprolactinemia --- too much prolactin in the blood --- or by pressure of the tumor on surrounding tissues.
                
Prolactin stimulates the breast to produce milk during pregnancy.  After giving birth, a mothers prolactin levels fall unless she breastfeeds her infant. Each time the baby nurses, prolactin levels rise to maintain milk production.