Carotid body tumour

Section: Head and neck Curriculum: Curriculum, page 43

Definition

• A Paragangliomas of the chemoreceptor cells located at the carotid bifurcation

Epidemiology


• People living at high altitudes

• OSA

• 40-60yrs

Aetiology


• Unclear - ?Chronic Hypoxia leading to carotid body cell hyperplasia

• 50% have genetic cause
  • Paraganglioma syndrome
  • MEN syndromes 2A and 2B
  • Neurofibromatosis Type 1
  • Von-Hippel-Lindau disease
  • Carney-Stratakis dyad
  • Carney triad

Clinical


• Painless slow growing lump
  • Carotid triangle - upper neck below angle of mandible
• Dysphagia
• Hoarseness
• Horner syndrome
• CN deficit - CN7, 9, 10, 11, 12
• Rubbery non tender mass lateral neck
• Carotid bruit
• Pulsatile
• <5% secrete catecholamines

• Fontaine’s sign - Moves freely in horizontal but not vertical plane


Pathology


• Normal carotid body is 3-6mm nest of cells 

• Local invasion of structures

• 5% malignant
• May be multicentric 


Histology

• Epithelioid cells arranged in compact cell nests or trabecular patterns (the so-called Zellballen appearance)

Investigations


• Duplex USS - highly vascular mass at the bifurcation

• Angiogram - characteristic blush at carotid bifurcation

• CT - homogenous mass with delayed washout (like a phaeo)

• Genetic testing

• Biochemical - plasma metanephrines, urine catecholamines

Classification

Shamblin Criteria

• Class I - localized, splaying of bifurcation, little attachment to carotids
• Class II - partially surround carotids
• Class III - intimately surround the carotids

Management


• Surgery is the only cure

• Malignant or Functional

  • Complete excision along subadventitial space

  • +/- arterial reconstruction

• Surgery
  • Indications
    • Secreting tumours
    • Mass effect
    • Only cure
  • Technical
    • Preadventitial dissection - avoid carotid artery injury
    • Preserve local nerves
• Radiation
  • Unresectable tumour

Prognosis

• Slow growing