POMC and pituitary tumor: CS can be caused by a corticotroph pituitary tumour overproducing ACTH [Cushing’s disease (CD)] in about 70%, an adrenal tumour or bilateral adrenal hyperplasia or dysplasia overproducing cortisol (adrenal CS) in about 20%, and an extra-pituitary tumour overproducing ACTH or, rarely, corticotrophin-releasing hormone (CRH) (ectopic CS) in about 10% of cases [1, 2].