2 Oct 2026 · Case #027
Pheochromocytoma
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Diagnosis
Pheochromocytoma
First-line treatment
Alpha blockade, then surgical adrenalectomy
How the diagnosis is reached
Hypertension that comes and goes is a different disease from hypertension that stays. Essential hypertension does not let a blood pressure fall to 128 between attacks and climb to 238 during them, and it does not resist three agents at once. Paroxysmal headache, sweating and palpitations with complete normality in between are the classic triad, and the episodic pattern is the whole point of it. The detail worth noticing is that a beta blocker made an attack worse: blocking beta-2-mediated vasodilatation in the presence of circulating catecholamines leaves alpha-mediated vasoconstriction unopposed, and this is precisely why alpha blockade must always come first. Weight loss despite good appetite reflects the hypermetabolic state, and the impaired fasting glucose comes from catecholamine-driven insulin suppression. Plasma free metanephrines are the screening test of choice because catecholamines are secreted episodically while their metabolites are produced continuously within the tumour, so a level drawn between attacks remains informative. An unenhanced attenuation above 10 Hounsfield units argues against a benign adenoma, and MIBG confirms functional chromaffin tissue. The family history of adrenal and thyroid surgery raises MEN2, which warrants RET testing and screening for medullary thyroid carcinoma before any operation. The cure is surgical, but the sequence is the examinable part. Alpha blockade with phenoxybenzamine or doxazosin is established for 10 to 14 days first, alongside liberal salt and fluid, because those cool peripheries are a chronically vasoconstricted and contracted plasma volume that will collapse the moment the vasoconstriction is taken away. Only then may a beta blocker be added for tachycardia, and never before, for the reason her own attack demonstrated. Handling the tumour releases a catecholamine surge and removing it is followed by abrupt hypotension, so both are anticipated with invasive monitoring rather than discovered.
Key clinical clues
- Paroxysmal headache, sweating and palpitations with complete normality in between
- Home readings swinging between 128 and 238 mmHg; resistant to three agents
- A beta blocker made an attack worse: unopposed alpha stimulation
- Raised plasma free metanephrines, informative even between attacks
- Family history of adrenal and thyroid surgery suggesting MEN2
The case in full
Presenting complaint
Patient history
A 39-year-old woman describes attacks that come on without warning: a pounding headache, drenching sweats and a racing heart, with a sense of impending doom. Each lasts about 20 minutes. She is entirely well between them.
Blood pressure record
Vital signs
She has been keeping home blood pressure readings for six weeks. Two were taken during attacks.
Examination and background
Physical examination
Examination between attacks is normal apart from a blood pressure of 138/84 and cool peripheries. She has lost 6 kg over four months despite a good appetite. Three antihypertensives have failed to control her readings, and a beta blocker made an episode markedly worse.
Laboratory results
Laboratory results
Screening bloods are sent.
| Parameter | Value | Reference |
|---|---|---|
| Plasma free metanephrines | 4.8 nmol/LRef <0.5 | <0.5 |
| Plasma normetanephrines | 9.2 nmol/LRef <0.9 | <0.9 |
| Fasting glucose | 132 mg/dLRef 70–110 | 70–110 |
| Corrected calcium | 9.6 mg/dLRef 8.5–10.2 | 8.5–10.2 |
| TSH | 1.8 mIU/LRef 0.4–4.0 | 0.4–4.0 |
| Potassium | 4.2 mmol/LRef 3.5–5.1 | 3.5–5.1 |
Cross-sectional imaging
Imaging
CT of the abdomen shows a 4.2 cm right adrenal mass with heterogeneous enhancement, central necrosis and an unenhanced attenuation of 42 Hounsfield units.
Functional imaging and family history
Clinical course
MIBG scintigraphy shows avid uptake confined to the right adrenal lesion. Her father had an adrenal operation in his forties; her paternal aunt had thyroid surgery for a tumour in her thirties.