Prolactin-secreting adenomas: pathogenesis, diagnosis, and management

Hyperprolactinaemia can result from physiological causes, pharmacological agents, or pathological conditions such as prolactin-secreting pituitary adenomas and other pituitary stalk-compressing masses. Sporadic prolactinomas are the most common functioning pituitary adenomas, with a female predominance during reproductive years. In men, these adenomas are usually larger and more aggressive. Prolactinomas are characterised by positive immunostaining for prolactin, pituitary-specific positive transcription factor 1, and oestrogen receptor α. Dopamine agonists, particularly cabergoline, are typically used as primary therapy. Treatment with up to 2·0 mg per week of cabergoline for at least 6 months normalises prolactin concentrations, achieves adenoma shrinkage of at least 30%, and restores gonadal function in most patients. Transsphenoidal surgery is increasingly used as primary therapy for small prolactinomas given a high chance of remission; transsphenoidal surgery is also indicated for patients with dopamine agonist intolerance or resistance. Radiotherapy is reserved for treatment-refractory prolactinomas. Multidisciplinary management and an individualised approach are key to maximising therapeutic responsiveness and optimising outcomes. In this Review, we assess evidence relating to pathogenesis, diagnosis, and management of prolactinomas, and highlight opportunities for future research.