Combined absence of CT-detectable nodules and low AVS lateralization index identifies risk of incomplete biochemical success in primary aldosteronism
Tim Nilsson, Henrik Falhammar, Christofer Juhlin, Adam StenmanAbstract
Introduction
The individual roles of CT findings and adrenal vein sampling (AVS) in primary aldosteronism (PA) are known, but their combined value for predicting outcomes in a CYP11B2-guided cohort is unclear. The aim of the study was to evaluate whether preoperative CT and AVS lateralization index (LI) are associated with histopathological subtype and postoperative outcomes (PASO) in patients undergoing adrenalectomy for PA.
Methods
This retrospective study included 121 surgically treated PA patients at Karolinska University Hospital 2017–2025. Patients were diagnosed according to CYP11B2-guided HISTALDO classification. Outcomes were assessed using PASO criteria.
Results
CT demonstrated unilateral nodules in 69%, bilateral findings in 9%, and no detectable nodules in 21%. Median nodule size was 14 mm (IQR 10–18). Classical histology (solitary CYP11B2-positive nodules) was present in 50%. CT findings correlated strongly with histopathological subtype: absence of nodules was more common in non-classical (multifocal/diffuse CYP11B2 expression) than in classical histology (40.0% versus 3.3%, P < 0.001), and classical histology was associated with larger nodules. AVS LI did not differ between histological groups. Patients with both absent CT nodules and AVS LI ≤10 had a markedly increased risk of biochemical non-success: 58.3% failed to achieve complete biochemical success compared with 21.1% in the remaining cohort (P < 0.01).
Discussion
CT findings, but not AVS LI, are associated with histopathological subtype in PA. Neither modality alone predicts biochemical outcome. However, combining absent CT nodules with AVS LI ≤10 identifies a subgroup with substantially increased risk of incomplete biochemical success, supporting consideration of non-surgical management in selected cases.