Dr. Maha Al Marashi

 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

 BGHx:
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Left carotid body tumour embolizaion
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Appendectomy as a child
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Tonsillectomy as a child

 Medications:
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Nil
 Allergies:
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Nil

 Family Hx:
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Grandfather – Carotid body tumour
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Brother – Carotid body tumour bilaterally

 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.

 Duplex scan of carotids
 Bilateral masses in the region of the carotid body at the bifurcation of the internal and external carotids.
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Right is smaller and more vascular.
Left encases vasculature.

 Genetic screening:

 Right carotid body tumour excision

 Histology:

 Discharged home day 2 post op with no complications
 Simple analgesia and aspirin
 For OPD follow up in 4 weeks.

 Bifurcation of the common carotid artery
 Right side coming of the brachiocephalic artery
 Left side from arch of aorta

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Thyroid gland
Trachea
Brachiocephalic artery
Common carotid artery
Internal jugular vein
Superior vena cava

 Derived from:
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Mesodermal elements of the third branchial arch
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Neural elements originating from the neural crest ectoderm
 Neural crests differentiate into forerunners of paraganglionic cells
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Paragangangliomas

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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

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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

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Chromaffin
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Capable of producing catecholamines
Non-chromaffin
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Initially, Carotid body tumours were thought to be non-chromaffin paragangliomas
≤5% of carotid body tumours are endocrinologically active
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May be part of the neurocristopathies e.g. MEN 1 & 2
Secondary tumours are common, including phaeochromocytomas

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Only known pathology is neoplasia
Most common of the non-chromaffin paragangliomas
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Shamblin et al described the following anatomic groups:
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

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Sporadic
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More common
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5% incidence of bilateral tumours
Familial
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Autosomal dominant
32% incidence of bilateral tumours
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Men:Women = 1:1
Screening of family members recommended
 Age
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Range between 20-80
Most apparent in 5 th decade

 Malignant potential
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Cannot be predicted by histological markers
Made by presence of lymph nodes or metastases
 Metastatic spread
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In region of lymph nodes
Kidney, thyroid, pancreas, cerebellum, lungs, bones, brachial plexus, abdomen and breast
Rate approximately 5%
 Predictors
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Severity of symptoms
Size at time of diagnosis

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Painless swelling in neck at the angle of the mandible
Non-specific
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Neck or ear pain
Local tenderness
Hoarseness
Dysphagia
Tinnitus
Occasionally
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Cranial nerve dysfunction
Rarely
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Lateralizing central neurological signs or symptoms
Neurosecretory
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Dizziness
Flushing
Palpitations
Tachycardia and arrhythmias
Headache and photophobia
Diaphoresis

 Neck mass below the angle of the mandible
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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

 Lymphoma
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Metastatic tumours
Carotid artery aneurysm
Thyroid lesions
Submandibular salivary gland tumours
Branchial cleft cysts

 Duplex scan with colour flow imaging
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Documents the highly vascularised mass in the area of carotid bifurcation
Tumour dimensions
Co-existent carotid occlusive disease
 Angiography
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Gold standard
Identifies collaterals, concurrent atherosclerosis and multicentric disease
 Dynamic or rapid sequencing CT
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Differentiates between aneurysm and neoplasm
Size and extent
 MRI
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Demonstrates relationship of tumour to adjacent structures
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Differentiate from other soft tissue lesions at base of skull
Size and extent

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Mainstay is complete surgical excision due to:
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≥5% incidence of metastases
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Unrelenting growth of unresected tumours
Early excision decreases incidence of cranial nerve and carotid artery damage
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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
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Pros: Decrease vascularity and improve safety
Cons: thrombosis of ICA or cerebral embolization

 Carotid body tumours are slow growing and exhibit benign characteristics
 Can survive for long periods without surgical intervention
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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