Extensive personal experience. Validation of prolactin levels in menstrual disorders and in prolactinomas.

It is now well established that hyperprolactinaemia is not rare and in the majority of cases is caused by a pituitary tumor, a prolactinoma. However, despite a plethora of relevant publications there are still certain questions that have not been adequately addressed: 1. What is the upper normal level of serum prolactin beyond which the condition should be characterized as hyperprolactinaemia requiring evaluation by imaging. 2. What is the incidence of non-secreting adenomas of the pituitary that might be erroneously regarded as prolactinomas. 3. How long should medical treatment be continued in the case of a prolactinoma. In this communication an attempt is made to critically analyze results on prolactinaemia obtained in our laboratory over a long time period, a sort of “meta-analysis” of our previously published data, aiming at reaching certain conclusions with practical implications for the clinician. Particular emphasis is placed on the prolactin levels in various menstrual disorders observed in 2500 women.