Bilateral Adrenal Nodules Presenting With Mild Autonomous Cortisol Secretion

Abstract

Objective: Benign adrenocortical adenomas are frequently diagnosed on cross-sectional imaging performed for unrelated reasons. Up to 15% to 20% of adrenal nodules are bilateral, representing bilateral adenomas or primary bilateral macronodular adrenal hyperplasia.

Methods: Mild autonomous cortisol secretion (MACS), diagnosed based on an abnormal dexamethasone suppression test, is seen in 19% to 44% of patients with adrenal adenomas. Distinguishing unilateral from bilateral MACS in patients with bilateral nodules is important to guide appropriate therapy and relies on imaging phenotype, and, in some cases, on adrenal vein sampling.

Results: MACS is associated with cardiovascular morbidity, poor quality of life, frailty, and increased mortality. Reversal of MACS improves these outcomes; however, management of patients with bilateral MACS is challenging. Unilateral adrenalectomy in patients with bilateral nodules and MACS may lead to permanent remission (if MACS is unilateral), temporary remission, or improvement of the degree of MACS (if MACS is bilateral). No medical therapy is currently approved for MACS.

Conclusion: Here, we review the presentation, diagnosis, and management of patients with bilateral adrenal nodules and MACS.

Keywords: MACS; adenoma; adrenalectomy; diagnosis; macronodular hyperplasia.