Aldosterone-producing adenoma (APA) is a common curable cause of hypertension. Somatic mutations in five genes (KCNJ5, ATP1A1, ATP2B3, CACNA1D, and CTNNB1) have been found to cause the excess aldosterone production of two thirds of APAs [1-4]. KCNJ5 mutant APAs, the most common and largest, had explicit genotype-phenotype relationship - a low protein expression of KCNJ5 relative to their peritumoural zona glomerulosa (ZG) and a zona fasciculata-like composition [5-6]. Conversely for the other genes, controversy arises on whether they have the opposite cell phenotype [4,7-8]. This prospective study aim to to characterize the histopathological-specific mutation spectrum of APAs.