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

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.

From 1993 to 2013, 274 patients underwent adrenalectomy for incidentaloma. All patients underwent standardized clinical, hormonal and imaging assessments.

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.

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.