Phaeochromocytoma & paraganglioma

Question 1

HYPERTENSION

i) what age group of people with HTN would PCT be suspected in?
ii) what is primary HTN aka?
iii) give five causes of secondary HTN? (CHAPS)

Answer 1

i) young people
ii) primary = essential (assoc with positive family hx)
iii) cushings, hyperaldo, aortic coarctation, pheochromocytoma, steonsis of renal arteries

Question 2

PCT AND PARAGANGLIOMA

i) which are adrenal and which is extra adrenal?
ii) what does PCT secerete? (2) from which cells?
iii) where does paraganglioma arise from? (2)

Answer 2

i) PCT is adrenal and PG is extra adrenal
ii) PCT secretes excess catecholamines eg adrenaline, NA and DA
iii) PG arise from autonomic ganglia (symp and psym)

Question 3

SIGNS AND SYMPTOMS - PCT & PG

i) what are the three classic symptoms? what % of people are these present in?
ii) name four other symptoms

Answer 3

i) high BP, headache, sweating
ii) flushing, anxiety, palpitation, abdo pain, dizzy, tachycardia

Question 4

PCT

i) what is the incidence? does it affect F or M more?
ii) name four things that would trigger clinical suspicion
iii) what are the five P’s of symptoms?
iv) how long do ‘spells’ of symptoms usually last? name three things that can ppt them
v) which BP occurs in lots of patients? name a mechanism that can stimulate this

Answer 4

i) affects 0.01-0.1% of pop
- aff F and males equally

ii) clinical suspicion - severe HTN/crisis, refractory HTN when on >3 drugs, HTN at young age, adrenal lesion on imaging, family history
iii) Presure (HTN), Pain (headache), perspiration (sweating), palpitation, pallor, paroxysms

iv) spells - can last 10-60 mins, daily to monthly
- ppt by diagnostic procedures, drugs eg opioids, anaesthesia, histamine or strenous exercise

v) hypotension can occur
- loss of postural reflexes due to prolonged catecholamine stimulation

Question 5

FEATURES OF PCT

i) name two general symptoms
ii) name three cardiac related features
iii) is calcium high or low? what syndrome is this associated with?
iv) what metabolic condition may they have?
v) why may they get weight loss?
vi) give four differentials for PCT

Answer 5

i) N+V, abdo pain, severe constipation
ii) chest pain, congestive heart failure, cardiac dysrhythmia
iii) hypercalcaemia > associated with MEN2
iv) may have mild glucose intolerance / DM
v) weight loss due to lipolysis
vi) differentials - hyperthyroid, arrhythmia, hypoglycaemia, migrane, panic attack, ETOH withdraw

Question 6

INVESTIGATION FOR PCT

i) what investigation is done first?
ii) is biochemical testing done before or after imaging?
iii) name three biochem tests to be done
iv) give four indications when there may be a false positive in biochemical tests?

Answer 6

i) plasma free/urinary metanephrines (produc of DA/adren when metabolised)
ii) do biochem testing first then demonstrate excess catecholamine prod/metab in urine then image to confirm
iii) 24 urine collection, catecholamines, metanephrines
iv) false positives - sympathoadrenergic overdrive, extreme stress or illness, non supine position, renal insufficiency, diet (coffee tea, banana, choc, cocoa, vanilla), medication

Question 7

IMAGING FOR PCT

i) what may a CT scan look for? what is the sensitivity for adrenal and extra adrenal pheos?
ii) which functional scan can be done?
iii) which functional imaging technique is good for looking at metastatic disease?
iv) what is the most sensitive scan to use?

Answer 7

i) CT scan for adrenal mass
- adrenal phaeo = 93-100%
- extra adrenal - 90%

ii) MIBG
iii) use FDG PET CT to look for mets
iv) Galium dotatate

Question 8

PRE OP MANAGEMENT

i) which receptors need to be blocked? (2) why?
ii) name two drugs which can be given to block these
iii) what can be added if the patient is tachycardic
iv) how many days pre op should medical treatment be given?

Answer 8

i) block alpha and beta adrenergic receptors
- to prevent hypertensive crisis

ii) give phenoxybenzamine or daxozocin (alpha blockers)
iii) tachycardic > add propanolol
iv) give medical tx for 7-14 days

Question 9

FAMILIAL PHAEO

i) what % are familial?
ii) give four indications for genetic screening
iii) name four conditions related to familial PCT
iv) which mutation may be found in familail paraganglioma?
v) which mutation has the highest risk of mets?

Answer 9

i) 40% are familial
ii) genetic test if bilateral tumours, paraganglioma (extra adrenal), unilat with family hx, unilat and young age, mets
iii) Men2a, Men2b, VHL, NF1
iv) SDH mutation (involved in krebs and leads to pseudohypoxia)
v) SDHB mutation - extra adrenal and accounts for >60% of mets therefore screen regularly to prevent

Question 10

SUMMARY

i) name one thing that may arouse suspicion of PCT
ii) which type of tests are done first?
iii) what is the initial test done?
iv) in what position should bloods be taken from?
v) where may a mass be seen on imaging?

Answer 10

i) patients with paroxysms (spells)
ii) do biochem tests first then imaging
iii) do plasma or urine metanephrines first
iv) take bloods preferably after >30 min supine rest
v) supra renal mass