Phaeochromacytoma

Question 1

What cells produce adrenaline?

Answer 1

Chromaffin cells in adrenal glands

Question 2

What is pheochromocytoma?

Answer 2

Tumour in chromaffin cells (adrenal glands) -> excess adrenaline is produced

Question 3

What type of hormone adrenaline is?

Answer 3

Catecholamine

Question 4

Pattern of adrenaline secretion in Pheochromocytoma

Answer 4

secreted in bursts giving periods of worse symptoms followed by more settled periods

Question 5

What endocrine disorder is associated with pheochromocytoma?

Answer 5

MEN type II

Question 6

(2) investigations in suspected pheochromocytoma

Answer 6

• 24 hour urine catecholamines
• Plasma free metanephrines

Question 7

Do we measure serum catecholamines in Ix of pheochromocytoma?

Answer 7

No as it is unreliable because catecholamine results will fluctuate

*24 hour urine catecholamines - more reliable

Question 8

Metanephrines

• what they are
• diagnostic use

Answer 8

Metanephrines:

• breakdown product of adrenaline
• have longer half-life than adrenaline

* longer half-life -> less prone to fluctuations -> more reliable diagnostic tool

Question 9

Signs and symptoms of pheochromocytoma

Answer 9

*signs and symptoms relate to the periods when the tumour is secreting adrenaline -> fluctuate

• Anxiety
• Sweating
• Headache
• Hypertension
• Palpitations, tachycardia and paroxysmal atrial fibrillation

Question 10

Management of pheochromocytoma

Answer 10

• Alpha blockers (i.e. phenoxybenzamine)
• Beta blockers once established on alpha blockers
• Adrenalectomy to remove tumour is the definitive management

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