Are Nonfunctioning Adrenal Adenomas Necessarily Clinically Unimportant?

In a recent study, patients with adrenal incidentalomas and evidence for autonomous cortisol secretion (based on overnight 1-mg dexamethasone suppression testing) but without overt Cushing syndrome had excess risk for death (NEJM JW Gen Med Jul 1 2021 and Ann Intern Med 2021; 174:1041). Now, Swedish researchers have examined mortality risks for patients with presumed nonfunctioning adrenal adenomas (NFAAs) in a retrospective case-control study: 18,000 patients with a formal diagnosis of benign adrenal neoplasm — but no formal diagnosis of hormonal activity such as Cushing syndrome — were compared with 124,000 controls matched by age and sex.

After median follow-up of 6 years, 21% of NFAA cases and 16% of controls had died, the difference was…