pheochromocytoma Flashcards
1
Q
What is a phaeochromocytoma?
A
An adrenal medullar tumour of chromaffin cells that secrete catecholamines (NAd, Ad)
2
Q
Symptoms of phaeochromocytomas (4)
A
- Episodic headache
- Profuse sweating
- Palpitations
- Anxiety
3
Q
Signs of phaeochromocytomas (3)
A
- Hypertension (90%)
- Hypertensive retinopathy
- Tachycardia
4
Q
Tumour patterns in phaeochromocytomas (4)
A
- 10% bilateral
- 10% cancerous
- 10% familial
- 10% extra-adrenal (mc location: organ of Zuckerkandl at aortic bifurcation)
5
Q
Diagnosis of phaeochromocytoma (3)
A
- 24 hour urine metanephrine collection
- Plasma free metanephrines (GS)
- CT abdomen and pelvis
6
Q
Why are metanephrines measured to diagnose pheochromocytoma? (2)
A
- Adrenaline has a very short half life in blood (only a few minutes)
- Metanephrines are a breakdown product of adrenaline and have a longer half life
7
Q
Genetic associations of phaeochromocytomas (3)
A
- 25% familial and associated with MEN 2a+2b
- Neurofibromatosis 1 (tumours deposited along myelin sheath)
- Von-Hippel Lindau disease
8
Q
Treatment of phaeochromocytoma (3)
A
Peri-operative
- Alpha blocker first (eg: phenoxybenzamine)
- Then beta blocker (eg: atenolol, propanolol)
Surgical
- Laproscopic adrenalectomy
9
Q
Pheochromocytoma hypertensive crisis, causes and treatment (3)
A
- BP higher than 180/120
- Causes: XR contrast, tryclic antidepressants, opiates
- First line treatment: phentolamine (alpha blocker)
