Phaechromocytoma

Question 1

Pathophysiology

What causes 25% of cases?

Answer 1

A phaeochromocytoma is a tumour arising from sympathetic paraganglia cells which are collections of chromaffni cells

Usually found in in the adrenal medulla

There is a 10% rule to describe the patterns of tumour:
10% bilateral
10% cancerous
10% outside the adrenal gland (at aortic bifurcation
10% are familial (associated with MED 2, neurofibromatosis, Von Hippel-lindau syndrome

Question 2

Clinical Features

Answer 2

Smptoms tend to fluctuate with peaks and troughs relating to periods when the tumour is secreting adrenaline:

Anxiety
Sweating
Headache
Hypertension
Palpitations, tachycardia and paroxysmal atrial fibrillation

Question 3

Management

Answer 3

MEDICAL:
Alpha blockers (i.e. phenoxybenzamine)

Beta blockers once established on alpha blockers

Adrenalectomy to remove tumour is the definitive management

SURGICAL:
Patients should have symptoms controlled medically prior to surgery to reduce the risk of the anaesthetic and surgery.

Question 4

Investigations

Answer 4

• 24 hour urine or plasma metanephrines

- Adrenal CT: abdominal CT