PRL and Microprolactinoma: The patient was a 38-year-old woman diagnosed in 2015 with a 5 mm microprolactinoma (PRL 126 ng/mL) and showed complete resistance to dopamine agonists (last PRL prior to surgery while taking 3.5 mg per week of cabergoline: 175 ng/mL; IHC study: 100% positivity for PRL; negativity for the rest of pituitary hormones; cytokeratin AE1/AE3 100% cytoplasmic).