POMC and Cushing syndrome due to macronodular adrenal hyperplasia: Cushing syndrome (CS) can be exogenous (or ‘iatrogenic’) when glucocorticoids are used in high doses for a prolonged period of time or endogenous due to overproduction of cortisol either by an ACTH-producing pituitary tumor (also known as Cushing disease -CD-) or by an ACTH-independent ACT.