skip to main content

Alpha-blockade Phaeochromocytoma — SCE Medical Oncology MCQ

Instant feedback + full explanation. One question, done properly.

ModerateCancer GeneticsAlpha-blockade PhaeochromocytomaSCE Medical Oncology

A 50-year-old man with hereditary paraganglioma-phaeochromocytoma syndrome (SDHB mutation) develops a metastatic paraganglioma. His catecholamines are elevated. Before any biopsy or surgery, what MUST be done?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: B — Alpha-adrenergic blockade (phenoxybenzamine or doxazosin) for at least 10-14 days before ANY intervention — failure to adequately block catecholamine effects risks intraoperative hypertensive crisis, arrhythmia and death

MANDATORY pre-operative alpha-blockade (phenoxybenzamine or doxazosin, started 10-14 days pre-procedure) is required before ANY intervention (biopsy, surgery, angiography) for known or suspected phaeochromocytoma/paraganglioma. Tumour manipulation can trigger massive catecholamine release causing hypertensive crisis (BP >250/150), arrhythmia, stroke, MI and death. Alpha-blockade first → then add beta-blockade (ONLY after adequate alpha-blockade, otherwise unopposed alpha-stimulation causes paradoxical hypertension) → volume expansion (liberal salt/fluid intake). This sequence is critical for patient safety.

Reference: NICE; Endocrine Society Phaeochromocytoma Guidelines; ESMO NET