POMC and Cowden syndrome 1: In general outpatient clinics, the prevalence of CS is around 0.5% in the hypertensive population and <1% in patients with resistant hypertension.40 Only hypertensive patients with other clinical features of CS should undergo screening tests for CS.40 Endogenous CS can either be ACTH-dependent (80% of all cases) or ACTH-independent (20%).