POMC and medullary thyroid gland carcinoma: The rarest form of ACTH-dependent CS in children is ectopic Cushing’s syndrome (ECS), associated with ectopic production of ACTH or CRH, most commonly by neuroendocrine tumors such as bronchial carcinoids, gastrointestinal tumors, medullary thyroid carcinoma, or pheochromocytomas [2,4,5].