Phaeochromocytoma and endocrine hypertension — structured clinical encounter

Station brief (candidate)

You have ten minutes to assess this boy, establish the diagnosis, outline the investigation and preoperative management, and address the family's questions. The examiner will prompt you at intervals. A catecholamine-secreting tumour is the leading diagnosis, and the family is frightened by the severity of the spells. [4]

Key clinical features to elicit

The classic triad is severe headache, generalised sweating and palpitations, occurring in paroxysms with pallor and anxiety, between which the child looks well. The hypertension is sustained in children more often than it is episodic. Elicit the frequency, duration and triggers of the spells, any weight loss despite a good appetite, and a family history of endocrine tumours, sudden death or known syndromes (MEN2, VHL, neurofibromatosis). [4]

Diagnostic work-up

Confirm biochemically with plasma free metanephrines (highest sensitivity) or a twenty-four-hour urine fractionated metanephrines collection (highest specificity), because the tumour leaks metanephrines continuously while catecholamine release is episodic. Once positive, localise with MRI of the abdomen and pelvis, then functional imaging with iodine-123 MIBG scintigraphy or gallium-68 DOTATATE PET. Every child then has a hereditary gene panel. [1]

Preoperative preparation — the non-negotiable sequence

Alpha-blockade first, then beta-blockade. Start phenoxybenzamine at around 0.5 mg per kilogram per day and titrate over ten to fourteen days to the block-and-fill end-point — normotension or mild hypotension with an orthostatic drop and nasal stuffiness. Add a beta-blocker only once the child is fully alpha-blocked, to control reflex tachycardia. The order is never reversed, because a beta-blocker before an alpha-blocker leaves unopposed alpha-one vasoconstriction and precipitates a hypertensive crisis. [1]

Hereditary genetics and surveillance

Around forty percent of paediatric phaeochromocytomas and paragangliomas carry a germline mutation, so the gene panel is mandatory and covers SDHx, VHL, RET, NF1, TMEM127, MAX and FH. An SDHB result flags extra-adrenal paraganglioma with metastatic potential and converts the child onto lifelong malignancy surveillance. The family is offered cascade genetic testing once a mutation is found. [7]

Family conversation

Explain to the family that this is a catecholamine-secreting tumour that is highly treatable with careful preparation and surgery, that the preparation takes about two weeks of medication to make the operation safe, and that because the condition often runs in families, blood relatives will be offered testing. Reassure them that the spells will be controlled by the alpha-blockade and that a structured surveillance plan will follow the child into adult care. [2]