Phaeochromocytoma

Question 1

Define phaeochromocytoma

Answer 1

Tumour of the adrenal medulla that secretes catecholamines (noradrenaline/adrenaline. They arise from the chromaffin cells. Can also be extra-adrenal, found by the aortic bifurcation.

Question 2

Aetiology of phaeochromocytoma

Answer 2

Most phaeochromocytomas are sporadic, but there are some studies that suggest that up to 40% are hereditary in adults.
10% are part of hereditary cancer syndrome:
- thyroid
- MEN-2A and 2B
- Neurofibromatosis type 1
- von Hippel-Lindau syndrome (SDH mutations)

• 10% extra-adrenal
• 10% malignant
• 10% bilateral
• (10% familial)

Question 3

Symptoms of phaeochromocytoma

Answer 3

Triad of: headaches, sweating, tachycardia

Headaches
Diaphoresis
Palpitations
Panic attack or sense of doom/ anxiety/hyperactivity/confusion/episodic psychosis
Diarrhoea
Fever
Syncope
Angina
Dyspnoea

Can be precipitated by straining, exercise, stress, abdominal pressure, surgery, or by beta blockers, IV contrast agents, tricyclics.

Question 4

Signs of phaeochromocytoma on examination

Answer 4

General:
- Pallor
- Signs of Cushing’s: striae, centripetal obesity, moon face etc.
- Tremor

Obs:
- Hypertension (often episodic and severe after abdominal palpation)
- Orthostatic hypotension
- Tachycardia

Fundoscopy;
- Paplliodema
- Retinopathy

Abdo: ?mass palpable

Question 5

Investigations for phaeochromocytoma

Answer 5

24h urine metanephrines + metadrenaline (catecholamines and vanillylmandelic acid): raised
ECG: ?arrhythmia

FBC: raised WCC
Serum free metanephrines + normatenephrines: raised
Plasma catecholamines: raised (but high false + rate)
Genetic testing: ?VHL, MEN

CT abdo: localise tumour
MIBG (Meta-iodobenzylguanidine): uptake intensity is high in catecholamine-producing tissues

Question 6

Management for phaeochromocytoma

Answer 6

1. Alpha blockade with IV fluid as it commences (fluid prevents BP from dropping too quickly)
   a. Phentolamine IV 5-20mg (Short acting) → phenoxybenzamine PO (long acting)
   b. Prevents hypertensive crisis
   c. If inadequate BP control → CCBs e.g. nifedipine PO
2. Beta blockade e.g. atenolol PO
   a. Prevents tachycardia
3. Laparoscopic adrenalectomy
   4-6 weeks after presentation to allow alpha/beta blockade

+ high salt diet and hydration (expand volume)

+ Follow up every year for at least 10 years

Question 7

Complications of phaeochromocytoma

Answer 7

Acute hypertensive crisis
Neurological complications: hypertensive encephalopathy, intracerebral haemorrhage, CVA

Question 8

Prognosis for phaeochromocytoma

Answer 8

Benign:
- Surgery is curative in >85%
- 95% 5 year survival
- Recurrence <10%
Metastatic:
- No cure
- 5 year survival 42%