Accuracy of adrenal computed tomography in predicting the unilateral subtype in young patients with hypokalaemia and elevation of aldosterone in primary aldosteronism

Context: The current Endocrine Society Guideline suggests that patients aged <35 years with marked primary aldosteronism (PA) and unilateral adrenal lesions on adrenal computed tomography (CT) scan may not need adrenal vein sampling (AVS) before proceeding to unilateral adrenalectomy. This suggestion is, however, based on the data from only one report in the literature. Objective: We sought to determine the accuracy of CT findings in young PA patients who had unilateral adrenal disease on CT with hypokalaemia and elevation of aldosterone. Design and patients: We retrospectively studied 358 PA patients (n = 30, aged <35 years; n = 39, aged 35-40 years; n = 289, aged ≥40 years) with hypokalaemia and elevation of aldosterone and unilateral disease on CT who had successful AVS. Main outcome measure: Accuracy of CT findings is determined by AVS findings and/or surgical outcomes in patients aged <35 years. Results: Concordance of the diagnosis between CT and AVS was 90% (27/30) in patients aged <35 years, 79% (31/39) in patients aged 35-40 years and 69% (198/289) in those aged ≥40 years (trend for P <.01). Surgical benefit was confirmed in three patients aged <35 years and in three patients aged 35-40 years with the available surgical data who had discordance between CT and AVS findings. Collectively, the diagnostic accuracy of CT findings was 100% (30/30) if aged <35 years and 87% (34/39) if aged 35-40 years. Conclusion: Primary aldosteronism patients aged <35 years with hypokalaemia and elevation of aldosterone and unilateral disease on adrenal CT could be spared AVS.