Prolactinoma is a common type of pituitary tumor that affects the production of the hormone prolactin. It is the most prevalent type of pituitary adenoma, accounting for approximately 40-60% of all cases. Prolactinomas are more commonly diagnosed in women than in men, with an estimated prevalence of 1 in 1000 women. However, the actual prevalence may be higher as many cases go undiagnosed. Prolactinomas can cause various symptoms, including irregular menstrual periods, infertility, and milk production in non-pregnant women. Treatment options include medication and surgery.