Carotid Body Tumor

Carotid Body

• • Normal carotid body 3-6 mm

  • Nest of chemoreceptor cells of neuroectodermal origin

  • Responds to decrease in Po2, increase in Pco2, decrease in pH, or blood temperature increase

  • Results in increase in blood pressure, heart rate, depth and rate of respiration

Carotid Sinus

• • Baroreceptor

  • Stimulation causes reflex bradycardia and hypotension

  • Tumors of carotid body

  • -Cervical chemodectomas

    -Paragangliomas

    -Glomus tumors

    -Nonchromaffin paragangliomas

  • 10% metastatic

  • Histologically, tumors resemble normal carotid body

  • Often extends to local structures

Epidemiology

• • Incidence equal in genders

  • Bilaterality is common when tumor is familial

  • Incidence increased in hypoxic persons (cyanotic heart disease, high altitude)

Symptoms and Signs

• • Slow enlargement of asymptomatic cervical mass

  • Rarely, hypertension secondary to release of catecholamines

  • Rarely, cranial nerve dysfunction from tumor extension

  • Solitary midlateral pulsatile neck mass that is firm and rubbery

  • Mass mobile in horizontal plane not vertical plan

  • 50% bruits

Imaging Findings

• • Duplex scanning is often diagnostic

  • Angiography: Characteristic tumor blush at carotid bifurcation, with wide separation of internal and external carotid arteries

• • Duplex scanning often diagnostic

  • Angiography shows characteristic tumor blush at carotid bifurcation, with wide separation of internal and external carotid arteries

  • Percutaneous needle or incisional biopsy is dangerous

• • Physical exam

  • Cervical US

  • CT scan or MRI

  • Genetic counseling for succinyl dehydrogenase mutation screening (SDH-D and SDH-B)

• • Preferred treatment: Complete excision and possible arterial reconstruction

  • Radiation therapy and chemotherapy not helpful

  • Preoperative embolization carries risk of stroke and generally not performed

Complications

• • > 40% incidence of cranial nerve dysfunction after resection

References