Phaeochromocytoma Flashcards
What is phaeochromocytoma?
A rare, benign tumour of the chromaffin cells in the adrenal gland
What is the function of chromaffin cells?
The secretion of adrenaline
How do phaeochromocytoma’s affect adrenaline levels?
It results in excessive production of adrenaline
What is adrenaline?
It is a catecholamine hormone and neurotransmitter that stimulates the sympathetic nervous system
What pattern do phaeochromocytoma’s follow?
10% rule
Describe the 10% pattern rule that phaeochromocytoma’s follow
10% Bilateral
10% Malignant
10% Extra-Adrenal
10% Hyperglycaemia
What are the two risk factors associated with phaeochromocytoma?
Genetics
Familial syndromes
What four genes are associated with phaeochromocytoma?
SDHD Gene
RET Gene
VHL Gene
NF1 Gene
What four familial syndromes are associated with phaeochromocytoma?
Multiple Endocrine Neoplasia Type 2 (MEN 2)
Von Hippel-Lindau Disease
Neurofibromatosis One (NF1)
Hereditary Paraganglioma Syndromes
What is MEN 2 disease?
MEN 2 is a disorder that results in tumours in more than one part of the endocrine system
What is Von Hippel-Lindau disease?
Von Hippel-Lindau disease can result in tumours at multiple sites, including the CNS, endocrine system, pancreas and kidneys
What is neurofibromatosis one (NF 1)?
Neurofibromatosis results in multiple tumours in the skin (neurofibromas), pigmented skin spots and tumours of the optic nerve
What are hereditary paraganglioma syndromes?
Hereditary paraganglioma syndromes are inherited disorders that result in either phaeochromocytomas or paragangliomas
Describe the cycle of phaeochromocytoma clinical features
Phaeochromocytoma results in adrenaline being secreted in bursts, giving periods of worst periods followed by more settled periods
What are the seven clinical features of phaeochromocytoma?
Hypertension
Headache
Sweating
Palpitations
Tremor
Pallor
Panic Attacks
Describe the presentation of hypertension in phaeochromocytoma patients
It is usually persistent, however, in some cases patients present with paroxysmal attacks of hypertension where bending down, coughing, etc increases their blood pressure
What are the four investigations used to diagnose phaeochromocytoma?
24 Hour Urine Test
Blood Test
CT Scan
M-Iodobenzylguanidine (MIBG) Scan
What is the gold standard investigation used to diagnose phaechromocytoma?
24 hour urine test of metanpehrines
How do we conduct the 24-hour urine test used to diagnose phaeochromocytoma?
In this test, the patient collects a urine sample every time they urinate during a 24-hour period
We then measure the level of catecholamine hormones and metanephrines within these samples
Why is the urine test for phaeochromocytoma conducted over 24 hours?
This is due to the fact that adrenaline levels fluctuate throughout the day and therefore a single result would be difficult to interpret
What is metanephrine?
A breakdown product of adrenaline
What specific blood test do we conduct to diagnose phaeochromocytoma? What result indicates phaeochromocytoma?
We measure the metanephrine plasma levels
If the plasma levels of metanephrine are elevated then a diagnosis is indicated
What is a MIBG scan?
A MIBG scan involves injecting patients with radioactive iodine-123, which is then taken up by the phaeochromocytoma and appears on nuclear imaging.
How do we treat phaeochromocytoma patients preoperatively?
We prescribe alpha blockers (phenoxybenzamine) and beta blockers (labetalol) drugs for seven to ten days before surgery
