PRL and hyperprolactinemia: According to many studies, the highest prolactin levels are found in patients with prolactinomas, whereas prolactin levels < 100 ng/mL are typically seen in individuals with macroprolactinemia, systemic diseases, drug-induced hyperprolactinemia, and pseudoprolactinomas (1,4,5,12), mainly represented by nonfunctioning pituitary adenomas (13).