POMC and Cowden syndrome 1: Endogenous CS has traditionally been considered a rare condition, with an estimated annual incidence of 1.8 to 3.2 cases per million population,1 although a recent study suggests the true incidence may be considerably higher, especially in individuals aged <65 years.2 CS can be classified as either adrenocorticotrophic hormone (ACTH)-dependent or ACTH-independent.