Phaeochromocytoma

Question 1

Define

Answer 1

Rare catecholamine-producing tumours

Arise from sympathetic paraganglia cells (=phaeochrome bodies) → Which are collections of chromaffin cells

Usually found within the adrenal medulla
Extra-adrenal tumours (paragangliomas) are rarer (10%), and

often found by the aortic bifurcation (the organs of Zuckerkandl)

• Dangerous but treatable cause of HTN

10% rule
10% are malignant, 10% are extra-adrenal 10% are bilateral, 10% are familial

Question 2

Causes

Answer 2

~90% are sporadic
10% are part of hereditary cancer syndromes (e.g. thyroid, neurofibromatosis, von Hipel-Lindau)

Sporadic cases are of unknown aetiology

Familial in up to 30%

Familial cases are seen in patients with:

• MEN2a
• von Hippel-Lindau syndrome
• Neurofibromatosis type 1

Question 3

Epidemiology

Answer 3

RARE

< 0.2% of hypertensive patients

Question 4

Signs

Answer 4

Classic triad:

Episodic headache, sweating, and tachycardia

• Heart: ↑HR, palpitations/VT, dyspnoea, faints, angina, MI/LVF, cardiomyopathy
• CNS: Headache, visual disorder, dizziness, tremor, numbness, fits, encephalopathy, Horner’s syndrome (paraganglioma), subarachnoid/CNS haemorrhage
• Psychological: Anxiety, panic, hyperactivity, confusion, episodic psychosis
• Gut: D&V, abdominal pain over tumour site, mass, mesenteric vasoconstriction.
• Others: Sweats/flushes, heat intolerance, pallor, ↑temperature, backache, haemoptysis.

Question 5

Signs

Answer 5

Hypertension

Postural hypotension

Pallor

Tachycardia

Fever

Weight loss

Question 6

Investigations

Answer 6

24 hr urine collection - check for catecholamine levels (and check for fractionated metanephrine levels)

• NOTE: metanephrines are metabolites of adrenaline

Plasma free metanephrines

Tumour localisation (MRI or CT)

I-MIBG scintigraphy (another way of visualising the tumour)

Screen for associated conditions

Genetic testing