Pheochromacytoma

Question 1

What is a pheochromacytoma?

Answer 1

Adrenal medullary tumour which secretes catecholamines

Question 2

What are catecholamines?

Answer 2

Neurohormones involved in stress responses.
eg dopamine and adrenaline

Question 3

What causes phaeochromocytoma?

Answer 3

Multiple Endocrine Neoplasia (MEN) type 2a and 2b
or
Neurofibromatosis 1 (tumours deposited along myelin sheath)

Question 4

What are symptoms of pheochromacytoma?

Answer 4

Hypertension
Pallor
Very sweaty
Tachycardic

Question 5

How do you diagnose phaeochromocytoma?

Answer 5

Plasma metanephrines and normetanephrines: increased levels as tumour producing more

(More sensitive readings than noradrenaline or adrenaline readings, has longer 1/2 life)

Urinary catecholamines
CT image of tumour

Question 6

How do you treat pheochromacytoma?

Answer 6

Alpha blocker first
eg. phenoxybenzamine

Then beta blocker
eg atenolol (prevents reactive vasoconstriction)

If surgery possible then excise tumour

Question 7

What are complications of phaeochromocytoma?

Answer 7

Hypertension crisis (bp over 180/120)

Question 8

How do you treat a hypertension crisis?

Answer 8

Give phentolamine (alpha blocker)