Phaeochromocytomas and Paragangliomas Flashcards
What are phaechromocytomas
catecholamine-producing tumours that usually arise form the chromaffin cells of the adrenal medulla
What are paragangliomas
extra-adrenal phaeochromocytomas
What do phaeochromocytomas mainly secrete
noradrenaline
What do familial phaeochromocytomas secrete
Large amounts of adrenaline
Familial cases of phaeochromocytomas may be seen in patients with what other conditions/ syndromes
MEN 2
VHL (von Hippel- Lindau)
Neurofibromatosis type 1
How common is pheochromocytoma in patients with MEN 2
50%
Describe the clinical presentation of a patient with pheochromocytoma
Headache
sweating
palpitations
Others include chest pain, dyspnoea, nausea, constipation or epigastric pain, tremor of weakness
What are some clinical signs of patients with phaeochromocytomas
pallor
tachycardia
hypertension
postural hypotension
What should patients with suspected pheochromocytoma be investigated with
2 or 3 measurements of 24 hour urinary catecholamines i.e. adrenaline, noradrenaline and dopamine
What is a more sensitive test to diagnose phaeochromocytomas
Measurement of normetanephrine and metanephrine
What medications can increase measured catecholamines and metanephrines
tricyclic antidepressants amphetamines ethanol caffeine, nicotine calcium channel blockers paracetamol
What is the treatment for phaeochromocytomas
Surgical resection - may resolve hypertension (75%)
Describe the preoperative preparation for a phaeochromocytoma
Alpha blocker (phenoxybenzamine) followed by a beta blocker (propranolol) for at least 2-3 weeks before surgery
What are some side effects of alpha blockers
postural hypotension
nasal stuffiness
What percentage of all phaeochromocytomas are malignant
10%
