POMC and Cushing syndrome due to macronodular adrenal hyperplasia: In this report, we describe a case of an ectopic ACTH secretion with a misleading localization of the responsible tumor due to a concomitant rectal carcinoma.<h4>Case presentation</h4>A 49-year-old man was referred to our Endocrinology Unit due to suspicion of Cushing's syndrome.