Computed tomography scan can be misleading in the lateralisation of aldosterone excess

Primary aldosteronism (PA) is characterised by aldosterone hypersecretion and represents a common cause of secondary hypertension. During diagnostic evaluation, it is essential to determine the aetiology of PA since the treatment of unilateral and bilateral disease differs significantly. Adrenal vein sampling (AVS) has been implemented as a gold standard test for the diagnosis of PA subtype. However, due to the AVS complexity, costs and limited availability, many patients with PA are being treated based on the computed tomography (CT) findings. In this article, we present two patients with discrepant CT and AVS results, demonstrating that AVS is the only reliable method for localising the source of aldosterone excess. LEARNING POINTS: CT is an unreliable method for distinguishing aldosterone-producing adenoma (APA) from bilateral adrenal hyperplasia (BAH). CT can be misleading in defining lateralisation of the aldosterone excess in case of unilateral disease (APA). AVS is the gold standard test for defining the PA subtype.