Transcript Carotid Body Tumour

Carotid Body Tumour
Dr. Maha Al Marashi
KM. 34 Female
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Elective admission for Right Carotid body
tumour excision
Had been referred initially to the vascular
service with bilateral carotid body tumours
Incidental finding with no local pressure
symptoms or systemic effects
KM. 34 Female
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BGHx:
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Left carotid body tumour embolizaion
Appendectomy as a child
Tonsillectomy as a child
KM. 34 Female
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Medications:
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Nil
Allergies:
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Nil
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Family Hx:
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Grandfather – Carotid body tumour
Brother – Carotid body tumour bilaterally
KM. 34 Female
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Ultrasound scan neck
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Evidence of bilateral
carotid body tumours of
the carotid bifurcation
consistent with carotid
body tumours.
Thyroid gland is normal.
No other abnormalities.
KM. 34 Female
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Duplex scan of carotids
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Bilateral masses in the
region of the carotid body at
the bifurcation of the
internal and external
carotids.
 Right is smaller and more
vascular.
 Left encases vasculature.
KM. 34 Female
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Genetic screening:
KM. 34 Female
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Right carotid body tumour excision
KM. 34 Female
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Histology:
KM. 34 Female
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Discharged home day 2 post op with no
complications
Simple analgesia and aspirin
For OPD follow up in 4 weeks.
Carotid body tumours
Anatomy
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Bifurcation of the
common carotid artery
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Right side coming of
the brachiocephalic
artery
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Left side from arch of
aorta
Anatomy
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Thyroid gland
Trachea
Brachiocephalic artery
Common carotid
artery
Internal jugular vein
Superior vena cava
Embryology
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Derived from:
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Mesodermal elements of the third branchial arch
Neural elements originating from the neural crest
ectoderm
Neural crests differentiate into forerunners of
paraganglionic cells
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Paragangangliomas
Physiology
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Chemoreceptors located in the
bifurcation of the common
carotid artery
Monitor changes in the oxygen
and CO2 content and pH of the
blood and rely that sensory
information to the hypothalmus
and brain stem to help them
control cardiovascular and
respiratory functions
Other cells in the carotid body
respond to blood temperature
and to certain chemicals, e.g.,
nicotine and cyanide.
Has extremely high blood flow
and oxygen consumption
Histology
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Resemble the normal
architecture of the carotid
body
Highly vascular
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Zellballen (cell nests)
“Sustentacular” cell
Epithelioid cell
Cytochemical techniques
have demonstrated:
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Adrenaline
Noradrenaline
Serotonin
Classification
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Chromaffin
 Capable of producing catecholamines
Non-chromaffin
Initially, Carotid body tumours were thought to be non-chromaffin
paragangliomas
≤5% of carotid body tumours are endocrinologically active
May be part of the neurocristopathies e.g. MEN 1 & 2
Secondary tumours are common, including
phaeochromocytomas
Pathology
Only known pathology is neoplasia
Most common of the non-chromaffin
paragangliomas
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Shamblin et al described the following anatomic
groups:
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Group 1: small tumours, minimally attached. Surgical
excision not difficult
Group 2: larger, moderate attachments. Can be resected,
but many require temporary intra-luminal carotid shunt
Group 3: very large, encase carotid arteries. Often require
arterial resection and grafting
Incidence
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Sporadic
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Familial
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More common
5% incidence of bilateral tumours
Autosomal dominant
32% incidence of bilateral tumours
Men:Women = 1:1
Screening of family members recommended
Age
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Range between 20-80
Most apparent in 5th decade
Biologic behaviour
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Malignant potential
 Cannot be predicted by histological markers
 Made by presence of lymph nodes or metastases
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Metastatic spread
 In region of lymph nodes
 Kidney, thyroid, pancreas, cerebellum, lungs, bones, brachial
plexus, abdomen and breast
 Rate approximately 5%
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Predictors
 Severity of symptoms
 Size at time of diagnosis
History
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Painless swelling in neck at the angle of the mandible
Non-specific
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Occasionally
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Cranial nerve dysfunction
Rarely
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Neck or ear pain
Local tenderness
Hoarseness
Dysphagia
Tinnitus
Lateralizing central neurological signs or symptoms
Neurosecretory
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Dizziness
Flushing
Palpitations
Tachycardia and arrhythmias
Headache and photophobia
Diaphoresis
Examination
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Neck mass below the angle of the mandible
Laterally mobile but vertically fixed
Non-tender, rubbery, firm and non-compressible
Often pulsatile
Bruit
Abnormalities caused by vagal or hypoglossal nerve
impingement
Horner’s syndrome (rare)
Palpate opposite side
Differential diagnosis
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Lymphoma
Metastatic tumours
Carotid artery
aneurysm
Thyroid lesions
Submandibular salivary
gland tumours
Branchial cleft cysts
Investigations
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Duplex scan with colour flow imaging
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Angiography
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Gold standard
Identifies collaterals, concurrent atherosclerosis and multicentric disease
Dynamic or rapid sequencing CT
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Documents the highly vascularised mass in the area of carotid bifurcation
Tumour dimensions
Co-existent carotid occlusive disease
Differentiates between aneurysm and neoplasm
Size and extent
MRI
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Demonstrates relationship of tumour to adjacent structures
Differentiate from other soft tissue lesions at base of skull
Size and extent
Management
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Mainstay is complete surgical excision due to:
 ≥5% incidence of metastases
 Unrelenting growth of unresected tumours
Early excision decreases incidence of cranial nerve and carotid
artery damage
 Most are in Shamblin’s group 2 or 3 at time of clinical
presentation
Radiation for local control of residual or recurrent disease
Chemotherapy has no role
Pre-operative embolization
 Pros: Decrease vascularity and improve safety
 Cons: thrombosis of ICA or cerebral embolization
Prognosis
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Carotid body tumours are slow growing and
exhibit benign characteristics
Can survive for long periods without surgical
intervention
Death due to asphyxia and intra-cranial
extension; Martin et al noticed death rate of
approximately 8% in untreated patients
Even after prolonged disease-free intervals,
local recurrence following surgical resection
described
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