Autonomous cortisol secretion (formerly subclinical Cushing's syndrome) is detected in a patient with an adrenal incidentaloma. According to the current European Society of Endocrinology (ESE) 2023 guidelines, which test is used as the primary screening tool for this condition?

• A 24-hour urinary free cortisol
• B Late-night salivary cortisol on two occasions
• C Morning serum ACTH measurement
• D 1 mg overnight dexamethasone suppression test (DST) with cortisol threshold ≥ 50 nmol/L ✓

Explanation

The ESE 2016 and 2023 updated guidelines recommend the 1 mg overnight DST as the screening test for autonomous cortisol secretion in adrenal incidentalomas. A post-DST cortisol ≥ 50 nmol/L (1.8 µg/dL) is the threshold. Urinary free cortisol and late-night salivary cortisol have lower sensitivity for mild autonomous secretion. ACTH is used after confirming hypercortisolism to localise the source, not as a primary screen.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.