Adrenalectomy for incidentaloma: lessons learned from a single-centre series of 274 patients

Background: Adrenal incidentalomas are increasingly diagnosed and include a wide spectrum of lesions from benign adenomas to secreting or malignant lesions. The aim of the present study is to report a large single-institution experience of patients undergoing surgery for adrenal incidentaloma with particular attention to their diagnosis and post-operative course and the evolution of surgical practice over time. Methods: From 1993 to 2013, 274 patients underwent adrenalectomy for incidentaloma. All patients underwent standardized clinical, hormonal and imaging assessments. Results: Patients were mainly female (63.1%; n = 173), and the median age of patients was 56.5 years. After a complete hormonal evaluation, 47.9% (n = 129) of incidentalomas were classified as secreting tumours, including 24.4% (n = 67) subclinical cortisol-secreting adenomas and 18.9% (n = 52) pheochromocytomas. Adrenocortical carcinomas represented 9.5% (n = 26) of incidentalomas, and the risk of malignancy was significantly correlated with tumour size. The conversion rate after laparoscopic adrenalectomy (90.9%; n = 249) was 3.2% (n = 8). The overall morbidity rate was 13.9%, which included a 4.4% rate of severe morbidity (Clavien-Dindo ≥3). From 2008 onwards, there was a significant decrease (P < 0.001) in the use of surgical approaches for non-secreting adenomas. Conclusion: After a complete work-up, half of the incidentalomas were classified as subclinical oversecreting adrenal lesions and 10% proved to be malignant adrenocortical carcinomas. The debatable use of surgical approaches for benign nonfunctioning adenomas significantly decreased over time. Keywords: adrenalectomy; adrenocortical carcinoma; incidentaloma; non-secreting adenoma; pheochromocytoma; subclinical cortisol-secreting adenoma.