Prof. A U Qureshi _ Diseases of Adrenal Medulla, Pheochromocytoma and Steps of Adrenalectomy

### Lecture on Pheochromocytoma and Adrenalectomy

**Pheochromocytoma** is a rare catecholamine-secreting tumor arising from the adrenal medulla, leading to paroxysmal hypertension, palpitations, sweating, and headaches. Diagnosis involves measuring plasma-free metanephrines and imaging studies like CT or MRI.

**Adrenalectomy**, the surgical removal of the adrenal gland, is the definitive treatment. Key surgical steps include:

1. **Preoperative Preparation**: Control hypertension with alpha-blockers followed by beta-blockers.
2. **Patient Positioning**: Lateral decubitus for posterior or laparoscopic approach.
3. **Incision**: Depending on the approach (laparoscopic vs. open).
4. **Mobilization**: Carefully dissect the adrenal gland while avoiding injury to surrounding organs.
5. **Vascular Control**: Identify and ligate the adrenal veins early to prevent catecholamine surge.
6. **Gland Removal**: Complete resection of the gland with minimal manipulation.
7. **Closure**: Secure hemostasis and close incisions.

Postoperative care involves monitoring for adrenal insufficiency and managing blood pressure.

1. DISORDERS OF THE ADRENAL
MEDULLA AND DIFFUSE
NEUROENDOCRINE SYSTEM

2. The neuroectodermal tissue
•Adrenalmedulla-phaeochromocytomas
(PCCs)
•Extra-adrenalparasympatheticand
sympatheticgangliaaretermed
paragangliomas(PGLs).

3. •ParasympatheticPGLsaresitedmainlyinthehead
andneck(HNPGLs)
•95%Non-functional–Pressuresymptoms.
•Carotid body, vagal and jugulotympanic.
•SympatheticPGLsusuallysecretecatecholamines.

4. •1% to 25% extra-adrenal pheochromocytomas (paragangliomas),
•A network of chromaffin-producing neural crest tissue that
anatomically parallels the sympathetic and
parasympathetic ganglia
•Paragangliomas can arise in the head, neck, thorax, abdomen, and
pelvis(including the bladder).
•Aortic Bodies and Organ of Zuckerkandl
Pheochromocytoma

5. Clinical Features
Biochemical tests
Appropriate Imaging
Pheochromocytoma

6. Pheochromocytoma
The triad of headache, episodic
sudden perspiration, and tachycardia
is a classic hallmark of
pheochromocytoma

7. Pheochromocytoma
The triad of headache, episodic
sudden perspiration, and tachycardia
is a classic hallmark of
pheochromocytoma

8. Pheochromocytoma
The triad of headache, episodic
sudden perspiration, and tachycardia
is a classic hallmark of
pheochromocytoma
(90%)

10. Paroxysms may be precipitated by
Physical trainiAnesthesia Drugs

11. Clinical Features
Biochemical tests
Appropriate Imaging
Pheochromocytoma

12. Diagnosis of PPGL
Raised 24-hour
urinary excretion
of fractionated
metanephrines.
Metanephrines
in plasma

13. MetaNephrine
4X

14. Clinical Features
Biochemical tests
Appropriate Imaging
Pheochromocytoma

15. CT FINDINGS
•Well-circumscribed lesions.
•Richly vascularity and low lipid content, T
•Typically greater than 10 HUon unenhanced CT
•(mean approx. 35 HU).
•Differentiate them from lipid-rich adenomas

19. MRI
•Classically, bright signal intensity on T2-
weighted imaging (best seen on fat suppression
sequences)—termed the light bulb sign—
•believed to be diagnostic for pheochromocytoma.

21. What is the Gold Standard investigation to
diagnose Pheochromocytoma ?
Fluorine-18 fluorodeoxyglucose positron
emission tomography (18F-FDG PET) –
•the gold standard imaging modality for definitive staging in patients
with pheochromocytoma

22. y68Ga-DOTATE PET/CT

27. Indications for non-functional
> 6 cm
Suspicious
4 -6 cm
20% size /
5mm

29. Pre-operative
optimization

30. α-Blockade. Phenoxybenzamine
•Catecholamine blockade -Irreversibly blocks
•7 to 14 days before surgery.
•Oral 10 mg bid -increment 10/20 mg to a BP 130/80 mm Hg in
a seated position.
•Mild postural hypotension with SBP > 80 mm Hg is acceptable
•1 mg/kg is usually sufficient
•Because of the irreversible nature of α-blockade, require
transient blood pressure support after tumor resection

31. β-Blockade.
•Reflex tachycardia and arrhythmias that can result on initiation of α-
blockade.
•Should never be started before appropriate α-blockade.
•Indeed, in the absence of α-blockade, β antagonists cause
potentiation of the action of epinephrine on α1 receptors resulting
from blockade of the arteriolar dilation at the β2 receptor.
•Selective β1 adrenoreceptor blockers, atenolol and metoprolol, are
usually preferred.

32. Catecholamine Synthesis Blockade. α-
Methyltyrosine
•Blocks the rate-limiting step in the biosynthesis of catecholamines by
inhibiting the tyrosine hydroxylase enzyme and thereby preventing
the conversion of tyrosine to L-dihydroxyphenylalanine (L-DOPA) (see
Fig. 106.4) (Pacaket al., 2001b). Approximately 3 days

35. Intravascular Volume Management
•Restoration of intravascular volume
•Intake of salt and fluid is encouraged once catecholamine blockade
has been initiated (Lenders et al., 2005).
•Moreover, most centers admit patients the day before surgery and
initiate aggressive intravenous fluid resuscitation.
•The last dose of phenoxybenzamine and/or metyrosineis usually
given on the night before surgery, and the next morning’s dose is
withheld.
•This approach minimizes potentially prolonged hypotension after
tumor resection

37. CONSENSUS STATEMENT
( ADRENO-CORTICAL TUMOURS) -2017
Thelaparoscopicapproachforasuspectedmalignantadrenalmass
withadiameteroflessthan6cm(ENSATstageIorII)withoutevidence
oflocalinvasionorsuspectedmetastaticlymphnodes,asanoption,
shouldberestrictedtohigh-volumecenters.Ifalaparoscopicapproach
isused,thetransperitonealapproachintheflankpositionmaybe
preferable

41. Open
Adrenalectomy

56. Adrenocortical carcinoma

57. Adrenocortical carcinoma
•Rareaggressivemalignancythatarisesfromtheadrenal
cortex.
•Prognosisispoor
•MostACCsaresporadic
•Genetictumoursyndromessuchas(MEN1),
familialadenomatouspolyposis/Li–FraumeniandLynch
syndromes.

58. Modified Weiss histopathological system
•SCORE>3
•KiPROLIFERATION
>6 mitoses/50
high-power fields
≤25% clear tumour
cells in cytoplasm,
abnormal
Abnormal Mitosis Necrosis Capsular Invasion

59. CLINICAL
PRESENTATION
•Hormonal
excess(50–60%)
•Abdominal
mass(30–40%).
•Incidentalomas.
•Cushing’s syndrome
or a mixed picture of
Cushing’s and
virilisationin women.
•Mineralocorticoid
•Feminisationin male
patients.

61. Radiology
•CTorMRI-size(>6cm),heterogeneousappearance,necrosis-
localinvasionandmetastaticdiseasearediagnostic.
•Commonsitesofmets-lungsandliver,(includethethorax).
•FDG-PETscanning-occultmetastaticA(SUVmax)>40or1.5
timeshigherthantheliverbothsuggestmalignanttumours.
•
11
C-metomidatePETmayimprovediagnosticaccuracy
•Adrenalbiopsyisdiscouragedandfine-needleaspirationcannot
distinguishbenignfrommalignanttumours.

62. Treatment
SurgeryChemoPalliation

63. European Network for the Study of Adrenal
Tumours(ENSAT) classification
•82%instageI(T<5cm;T1N0M0),
•61%instageII(T>5cm;T2N0M0),
•50%forstageIII(T-any+Infiltration[T3],Tumour
thrombus[T4],positivelymphnodes[N1]butno
distantmetastases
•13%forstageIV

65. Postoperative Management.
•If phenoxybenzamine used preop α-blockade -
hypotension
•A high catecholamine state, α2-adrenoreceptor
stimulation inhibits insulin release. Withdrawal
stimulus after tumor resection -rebound
hyperinsulinemia and subsequent hypoglycemia