A 35-year-old woman presents with hypertension, hypokalemia, and suppressed plasma renin activity. Aldosterone-to-renin ratio (ARR) is markedly elevated. CT adrenals show a 1.8 cm right adrenal adenoma. Which confirmatory test is the most appropriate next step before adrenalectomy?
- A Adrenal vein sampling (AVS) bilaterally ✓
- B 24-hour urinary aldosterone after salt loading
- C Fludrocortisone suppression test
- D Dexamethasone suppression test
Correct answer: A. Adrenal vein sampling (AVS) bilaterally
Explanation
Adrenal vein sampling (AVS) is required before adrenalectomy for primary hyperaldosteronism (Conn's syndrome) even when CT shows a unilateral adenoma, because CT has ~25% false lateralization rate. AVS confirms unilateral hypersecretion and guides surgical decision. Fludrocortisone suppression and saline infusion tests confirm the diagnosis of primary hyperaldosteronism but do not lateralize; dexamethasone suppression is for Cushing's syndrome.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.