Phaeochromocytoma

Question 1

What causes phaeochromocytoma?

Answer 1

Adrenal medulla tumour causing excessive production of catecholamine (Ad + NAd)
I.e. tumour of CHROMAFFIN CELLS= cells which produce catecholamine in the adrenal medulla

Question 2

What are the clinical features associated with phaeochromocytoma and why are the paroxysmal?

Answer 2

Weakeness and fatigue 
Headaches 
Sweating 
Palpitations 
Hypertension 
Paroxysmal AF 
I.e. signs of sympathetic NS activation 

Intermittent release of catecholamines

Question 3

What biochemical tests can be done to diagnose phaeochromocytoma? Why can’t you measure serum catecholamines?

Answer 3

24hr urinary catecholamines
-indicates levels of catecholamine that has been secreted by tumour in last 24 hrs

Plasma free metanephrines
-breakdown product of catecholamines which has a longer half life and doesn’t fluctuate as much so can be used to give better indication of serum levels

Serum levels of catecholamines fluctuate

Question 4

What imaging tests can be done to diagnose phaeochromocytoma?

Answer 4

Adrenal MRI

MIBG scan

Question 5

What are the treatment options? What needs to be done before treatment

Answer 5

Adrenolectomy i..e removal of tumour is definitive treatment

Pre-operative alpha blockade and beta-blockade to control symptoms prior to surgery to reduce the risks of anaesthesia