A Current Approach to Hyperprolactinemia

Abstract

Prolactin is a hormone secreted by the anterior pituitary lactotrophs and is controlled by the influence of hypotha-lamic dopamine. PRL stimulates the proliferation and differentiation of mammary cells for lactation. There are many causes for hyperprolactinemia, including analytical, physiological, pharmacological, pathological and idiopath-ic causes. Macroprolactin is a significant analytical cause of hyperprolactinemia, and the most common cause of pathological hyperprolactinemia is prolactin secreting ade-nomas. Symptoms of true hyperprolactinemia include ga-lactorrhoea, secondary amenorrhea, oligomenorrhea and hypogonadotropic hypogonadism. Larger macroadenomas can cause compressive symptoms on the pituitary gland or visual symptoms. A single measurement of serum PRL obtained at any time of the day can be used to diagnose hy-perprolactinemia. Macroprolactinemia should be excluded in all cases of hyperprolactinemia, and polyethylene glycol precipitation is a fast, convenient and inexpensive method to exclude macroprolactinemia. Other interferents that can cause falsely low prolactin readings include the hook effect, biotin and heterophilic antibodies. Physicians must know how to approach hyperPRL and exclude the most important differential diagnoses of prolactinomas.