This test, performed by administering 2 mg of dexamethasone every 6 hours over a 48-hour period, showed an adequate serum cortisol suppression, hence excluding the clinical suspicion of ectopic ACTH syndrome, which indeed is an extremely rare condition among the pediatric population, in contrast with adults where it accounts for about 15% of ACTH-dependent CS [15]. This evidence concerns the gene POMC and Cowden syndrome 1.