AKT · Endocrine/Adrenal

Phaeochromocytoma & paraganglioma

Catecholamine-secreting tumour of adrenal medulla (or extra-adrenal paraganglia)

Overview

A catecholamine-secreting tumour of the adrenal medulla (phaeochromocytoma) or extra-adrenal sympathetic ganglia (paraganglioma). Episodic catecholamine surges cause paroxysmal hypertension, headache, palpitations and sweating. The '10% tumour' and strongly hereditary (MEN2, VHL, NF1, SDH). Alpha-blockade BEFORE beta-blockade is the life-saving rule before surgery.

Recognise

Paroxysmal/episodic HEADACHE, palpitations, sweating and pallor with severe (often labile) hypertension
Anxiety, tremor, weight loss, hyperglycaemia; hypertension resistant to standard treatment or in a young person
Hereditary associations: MEN2 (with medullary thyroid cancer), von Hippel-Lindau, NF1, succinate dehydrogenase mutations

Red flags

Hypertensive crisis (can be precipitated by anaesthesia, beta-blockade alone, or contrast) → emergency
Unopposed beta-blockade can trigger a hypertensive crisis (unopposed alpha vasoconstriction)

Differentials & how to tell them apart

Essential/anxiety-related hypertensionno biochemical catecholamine excess; not truly paroxysmal with the classic triad

Thyrotoxicosispalpitations/tremor/weight loss but with abnormal TFTs

Panic disorderepisodic adrenergic symptoms but normal metanephrines

Carcinoid syndromeflushing + diarrhoea, raised urinary 5-HIAA (not metanephrines)

Investigations

Plasma free metanephrines or 24-h urinary metanephrines/catecholamines (the diagnostic test). Then localise: CT/MRI abdomen, MIBG scan. Genetic testing (MEN2/VHL/NF1/SDH).

Management

Alpha-blockade first, then beta-blockade, then surgical resection

1Confirm with plasma/urinary metanephrines, then localise (CT/MRI ± MIBG). Refer to endocrinology/surgery; genetic testing.Gate: ALWAYS alpha-block (phenoxybenzamine) BEFORE adding a beta-blocker — beta-blockade first leaves unopposed alpha vasoconstriction and can precipitate a fatal hypertensive crisis; ensure full alpha-blockade + volume repletion before surgery
2Surgical resection after adequate alpha-blockade; lifelong follow-up (recurrence/metastasis); screen relatives for the hereditary syndromes.

Alpha-blockade FIRST (phenoxybenzamine/doxazosin) — controls BP and allows volume re-expansion before surgery

Beta-blockade AFTER alpha-blockade — for tachyarrhythmia — only once alpha-blocked

Surgical resection (adrenalectomy) — definitive, after full alpha-blockade

Key points

Paroxysmal headache + palpitations + sweating + labile hypertension = phaeo; metanephrines confirm it. THE rule: alpha before beta. Always think MEN2/VHL/NF1 — and exclude phaeo before any surgery in medullary thyroid cancer.

Monitor & prognosis

BP, metanephrines post-op; genetic/family surveillance.

Curable if resected; 10% malignant.

Source: Endocrine Society; CKS