Pheochromocytoma hegazy

HEGAZY SURGERY

1. Dr.Mostafa Hegazy

2. Signs and Symptoms

3. Episodic headache
Sweating
Tachycardia

4. Other symptoms
•Sustainedorparoxysmalhypertensionisthemostcommon
sign,however5-15%havenormalbloodpressure
•Mildtosevereheadachein90%ofpatients
•Generalizedsweatingin60-70%
•Palpitations
•Dyspnea
•Generalizedweakness
•Panicattacktypesymptoms
•Pallor
•orthostatichypotension
•visualblurring
•papilledema
•weightloss
•polyuria

5. Pathophysiology

7. •Catecholamines exhibitperipheralnervous system
excitatoryandinhibitoryeffectsaswellasactionsinthe
CNSsuchasrespiratorystimulationandanincreasein
psychomotoractivity.
•Theexcitatoryeffectsareexerteduponsmoothmuscle
cellsofthevesselsthatsupplybloodtotheskinand
mucousmembranes.
•Cardiacfunctionisalsosubjecttoexcitatoryeffects,
whichleadtoanincreaseinheartrateandintheforce
ofcontraction.
•Inhibitoryeffects,areexerteduponsmoothmuscleofthe
gut,thebronchialtree,andbloodvesselsoftheskeletal
muscle.

8. •Inadditiontotheireffectsasneurotransmitters,
norepinephrineandepinephrinecaninfluencethe
rateofmetabolismbymodulatinginsulinsecretion
andbyincreasingtherateofglycogenolysisand
fattyacidmetabolism.
•Abnormalitiesincarbohydratemetabolismsuchas
insulinresistance,impairedfastingglucose,type2
DMcanoccure.

9. When to suspect Pheochromocytoma
Hyperadrenergic spellsegself-limitedepisodesofnonexertional
palpitations,diaphoresis,headache,tremor,pallor
Resistanthypertension (<0.2%ofpatientswithHTN have
pheochromocytoma )
Pre-disposingfamilialsyndromeegMEN2,NF1,VHL
Familyhistoryofpheochromocytoma
Incidentallydiscovered adrenalmass:3-10%provetobe
pheochromocytomas
Pressorresponseduringanesthesia,surgeryorangiography
OnsetofHTN<20yearsold
Idiopathicdilatedcardiomyopathy
Historyofgastricstromaltumororpulmonarychondromas (Carney
Triad)

10. DIAGNOSIS

11. Historically:measured 24hour urinary excretion of
catecholamines andtotalmetanephrines
Superiortest:plasmafractionatedmetanephrines vialiquid
chromatography withelectrochemicaldetectionortandemmass
spectrometry
96-100%sensitiveand85-89%specificandfallsto77%in
patients>60yearsold
Predictive value ishighand normal testexcludes
pheochromocytoma exceptinpatientswithearlypreclinical
diseaseandthosewithstrictlydopamine-secretingtumors

12. Tricyclicantidepressantsinterferewithassaymostfrequently
Clonidinesuppression testisconfirmatory when plasma
fractionatedmetanephrines arepositive:0.3mgisadministered
orally,plasmacatecholamines aremeasuredbeforeand3hours
afterthedose.Clonidinewillsuppresscatecholamines ifexcess
isduetoessentialhypertension,butwillremainelevatedin
pheochromocytoma
FollowupwithCTorMRIofabdomenandpelvis
ConsiderMIBGscintgraphywhereacompound resembling
norepinephrineistakenupbyadrenaltissueifclinicalsuspicion
remainshigh

13. Medications that increase
measured catecholamine levels
TCAs
Levodopa
Drugscontainingadrenergicreceptoragonistsegdecongestants
Amphetamines
Buspironeandmostpsychoactiveagents
Prochlorperazine
Reserpine
Withdrawalfromclonidine
Ethanol
acetominophen

14. Malignant Potential
10%oftumorsareextraadrenal,but95%arewithinabdomen and
pelvis
About10%ofallcatecholamine-secretingtumorsaremalignant
Histologicallyandbiochemicallyidenticaltobenigncounterparts
Localinvasionordistantmetastasescanoccuraslongas20years
afterresection
Metastaticlesionsshouldberesectedifpossible
RFAofhepaticandbonemetastasesmaybeeffectiveinselected
patients
Combinationchemotherapy canbeconsidered

15. Treatment

16. Startalpha-adrenergicblocker7-10dayspreoperatively
Phenoxybenzamine isdrugofchoice:irreversible,long-acting,
non-specificalpha-adrenergicagent
Initialdoseis10mgb.i.d.;doseisincreasedby10-20mgin
divideddosesevery2-3days;finaldoseusually20-100mgdaily
GoalBP<120/80seatedandSBP>90standing
Highsalt(>5000mgdaily)recommended on3rddayto
counteract catecholamine-induced volume contraction and
orthostasis,thoughcautionadvisedinpatientswithCHForCRI
Followingadequatealpha-blockade,betablockadeisinitiated2-3
dayspre-operativelyeg.Propranolol10mgq.6.h

17. NEVERstartbetablockadefirst;unopposedalphaadrenergic
stimulationcanleadtofurtherelevationinbloodpressure
Long-term treatment withselectivealpha1-adrenergic
blockerssuchasprazosin,terazosin,doxazosin
Calciumchannelblockersareprobablyaseffective,eg.
Nicardipine30mgb.i.d.
Additionofmetyrosine,adirectcatecholamine synthesis
inhibitor,mayimproveperioperativecourse,thoughmost
institutionsreserveforthosepatientswhocannottolerate
thetypicalalpha+betablockadecombination.Sideeffects
includesedation,depression,diarrhea,anxiety,nightmares,
crystalluria and urolithiasis, galactorrhea, and
extrapyramidalsigns