Highlights ■ Hyperprolactinemia can be present in non-functioning pituitary adenomas because of the stalk effect. ■ Absolute prolactin levels may not always be reliable in discriminating non-functioning pituitary adenomas from prolactinomas. ■ Prolactin normalization after 48 h of 0.25mg cabergoline intake could be a strong predictor of non-functioning pituitary adenomas (100% sensitivity and specificity). ABSTRACT Objective: Clinical, imaging, and laboratory differentiation between non-functioning pituitary adenomas (NFPAs) and prolactinomas can be challenging in clinical practice because of their similar presentation and […]