Phaeochromocytoma Flashcards
Definition
Tumor arising from catecholamine-producing chromaffin cells of adrenal medulla
Key diagnostic factors
presence of risk factors headache palpitations diaphoresis FHx endocrine disorders/associated cancer syndromes->thyroid, MEN 2A, neurofibromatosis, von-Hippel lindau hx prior phaeochromocytoma hypertension hypertensive retinopathy tachyarrhythmias and myocardial infarction pallor impaired glucose tolerance/diabetes mellitus panic attacks or a 'sense of doom'
Rule of 10%
10% are malignany
10% are extra-adrenal
10% are bilateral
10% are familial
What is an important extra-adrenal location
Aortic bifurcation
Classic triad
Headache
Sweating
Tachycardia
Investigations
- 24 hour collection for catecholamines, metaneprhines, normetaneprhines and creatinine->elevated, at least 2-3 X normal for all measurement
- Serum free metanephrine and normetanephrine->elevated
- Plasma catecholamines ->may be elevated
- Genetic testing->may reveal familial disorders->VHL, MEN 2, NF
- FBC->erythocytosis
- Calcium->+
- Potassium->hypokalemia
- I-123 MIBG has a similar structure to noradrenaline and so incorporates into neurosecretory granules of the phaeochromocytoma, creating an image.
MRI/CT abdomen and pelvis->increased attenuation on non-enhanced CT. High signal on T2 weighted
Management
Hypertensive crisis->phentolamine
W/O:
Phenoxybenzamine (a-blocker) + atenolol/metoprolol (after alpha blockade to prevent tachy and arrythmias)
Hydration + high salt diet (>5g/day)
+/- CCB Nifedipine
In benign tumor->following medical management->
Surgical excision
If malignant following medical->Surgical debulking, chemotherapy, nuclear/radiation or ablation
Follow up
Assess metanephrines and normetaneprhines 1 week to 10 days postoperatively
Yearly f/u for at least 10 years->malignant potential may occur late
Seek medical help if symptoms recur
Complications
Acute HTN crisis
Neurological complications
Postoperative-> avoid complications with IV fluid
