A 42-year-old woman presents with hypertension, hypokalemia, and metabolic alkalosis. Plasma aldosterone-to-renin ratio (ARR) is elevated at 35 (ng/dL)/(ng/mL/hr). Confirmatory testing with salt loading shows failure to suppress aldosterone below 10 ng/dL. CT adrenals show bilateral adrenal hyperplasia. What is the next best step?
- A Bilateral adrenalectomy
- B Start spironolactone and reassess
- C Adrenal vein sampling to lateralize aldosterone excess ✓
- D Repeat ARR after stopping antihypertensives
Explanation
Even with CT-documented bilateral adrenal hyperplasia, adrenal vein sampling (AVS) is mandatory before deciding on surgical versus medical management, because CT misclassifies lateralization in up to 37% of cases — a unilateral aldosterone-producing adenoma can be missed or a small contralateral nodule can be mistaken for the culprit. Bilateral hyperplasia on CT is managed medically with mineralocorticoid receptor antagonists, but AVS must first confirm true bilaterality. Proceeding directly to bilateral adrenalectomy without AVS or starting medical therapy without ruling out surgically correctable disease would be suboptimal.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
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Written and medically reviewed by the StethoPrep medical team.