19. Pheochromocytoma

Question 1

What is pheochromocytoma ?

Answer 1

Tumor of chromaffin cells in adrenal medulla producing a lot of catecholmines

Most of the time tumor benign

Question 2

What is the clinical manifestation of pheochromocytoma ?

Answer 2

Hypertonic - constant or paroxysmal 
Headache sweating 
Tachycardia 
Flushing 
Weight losss
Anxiety

Question 3

What is the diagnosis of pheochromocytoma

Answer 3

plasma free metanephrien test

catecholamines and metanephrines in 24hr urine

Clonidine test
rules out stress induced or hypertensive induced catecholamines
Clonidine blocks alpha 2 receptors
= should be decrease in conc of catecholamines

Pheochromocytoma there is no decrease of catecholmine concentration

, Mri , Ct
Can locate tumor

rule out drugs such as methyl dopa use
coffee tea = which can effect urinary metenphrine

Question 4

What is the therapy of pheochromocytoma?

Answer 4

Before surgery patient treated with phenoxybentamine - irreversible blockage of alpha receptors = normal BP

Beta blockers - decrease HR

Removal of surgical tumor

Post op - check hypotension

——-
Tumor no surgically removable
Adrenoreceptor blockage - phenoxybentamine and prazosin
Metyrosine - block catecholmine synthesis

Question 5

What are the complication of pheochromocytoma ?

Answer 5

Hypertensive crisis - lung edema , intracranial haemorrhage , myocardial infarction , arrythmia

Question 6

etiology of pheochromocytoma ?

Answer 6

MEN2A , MEN2B

neurofibromatosis