Endocrinology and metabolic medicine for MRCPI Part 2

A 42-year-old woman presents with 6 months of episodic headache, palpitations and drenching sweats, with paroxysmal hypertension up to 220/120 mmHg between normal readings. Plasma metanephrines are four times the upper limit of normal. CT shows a 4 cm right adrenal mass. What must happen before surgery?

1. Beta blockade first to control the tachycardia Wrong, and dangerous. Unopposed alpha stimulation after beta blockade causes severe vasoconstriction and hypertensive crisis. This sequencing error is the single most examined point about phaeochromocytoma.
2. Biopsy of the adrenal mass to confirm the diagnosis Wrong and contraindicated. Biopsying a phaeochromocytoma can precipitate a catecholamine crisis, and the diagnosis is already made biochemically.
3. Immediate surgery without pharmacological preparation Wrong. Handling an unblocked tumour releases a catecholamine surge that can cause hypertensive crisis, arrhythmia and death on the table.
4. A course of high-dose corticosteroids Wrong. Steroid cover is relevant to adrenal insufficiency and to bilateral adrenalectomy, not to preoperative preparation for a unilateral phaeochromocytoma.
5. Alpha blockade established first, with beta blockade added only afterwards if needed correct Correct. Phaeochromocytoma requires alpha blockade, typically phenoxybenzamine or doxazosin, for one to two weeks preoperatively with liberal salt and fluid to re-expand the contracted plasma volume. Beta blockade is added only after alpha blockade is established.

The point: Alpha before beta, always. Screen for the associated syndromes, MEN2, von Hippel–Lindau, neurofibromatosis type 1, and the succinate dehydrogenase mutations, because a substantial minority are hereditary and that changes family screening.

Source: Endocrine Society clinical practice guideline — phaeochromocytoma and paraganglioma Endocrine Society · tier 2, specialty society or college