Endocrinology and metabolic medicine for MRCP Part 2

A 46-year-old man has resistant hypertension on three agents and a potassium of 3.1 mmol/L. Aldosterone-to-renin ratio is markedly raised. CT shows a 1.2 cm LEFT adrenal adenoma. Adrenal vein sampling shows lateralisation to the RIGHT adrenal. What is the most appropriate management?

1. Left adrenalectomy, targeting the visible adenoma Wrong, and the trap. The CT lesion is a non-functioning incidentaloma; removing it leaves the aldosterone-producing tissue in place and the hypertension uncured.
2. Bilateral adrenalectomy Wrong. It creates lifelong adrenal insufficiency to treat unilateral disease.
3. Lifelong spironolactone without surgery Reasonable if disease were bilateral or the patient unfit, but sampling demonstrates unilateral, potentially curable disease.
4. Repeat CT with adrenal protocol in 6 months Wrong. The functional question has been answered definitively by sampling. More imaging adds nothing and delays cure.
5. Right adrenalectomy correct Correct, and the point of the question. Adrenal vein sampling is the reference standard for lateralisation in primary aldosteronism and it overrides CT. Non-functioning incidentalomas are common, so operating on the side the scan shows rather than the side the sampling shows fails to cure the patient.

The point: In primary aldosteronism, adrenal vein sampling beats CT for lateralisation, particularly over the age of 35 when non-functioning adenomas are common. Confirm the biochemistry, then sample, then operate on the side that lateralises.

Source: Endocrine Society clinical practice guideline — primary aldosteronism Endocrine Society · tier 2, specialty society or college