The primary bilateral macronodular adrenal hyperplasia or the independent adrenocorticotropic hormone bilateral nodular adrenal hyperplasia is a rare cause hypercortisolism, its diagnosis is challenging and there is no clear way to decide the best therapeutic approach. Adrenal venous sampling is commonly used to distinguish the source of hormonal production in patients with primary hyperaldosteronism. It could be a useful tool in this context because it might provide information to guide the treatment. We report the case of a patient with ACTH independent Cushing syndrome in whom the use of adrenal venous sampling with some modifications radically modified the treatment and allowed the diagnosis of a macronodular adrenal hyperplasia.