These tumors arise from chemoreceptor zone present at the division of carotid artery ( supplying arterial blood to face – external carotid artery and brain- internal carotid artery) into external and internal carotid artery as shown in the figure.
PRESENTATION : usually presents as a painless neck mass, but larger tumors may affect cranial nerve , usually of the vagus nerve (leading to change or heaviness of voice) and hypoglossal (tilting or deviation of tongue towards the side of tumor) nerve. These are highly vascular tumors means have many small blood vessels around it.
INHERITANCE : 3 different types
The sporadic (does not genetic link) form is the most common type, representing approximately 85% of carotid body tumors . The familial(have genetic link) type (10-50%) is more common in younger patients. The hyperplastic form is very common in patients living at a high altitude (> 5000 feet above sea level) due to decrease level of oxygen .
About 5% of carotid body tumors are present on both sides of neck and 5-10% can be cancerous also, but these rates are much higher in patients with inherited disease.
Individuals with malignant (cancerous) carotid body tumors may have higher blood pressure .
DIAGNOSIS : The test performed are ultrasonography with color Doppler, CT scanning of the head and neck with contrast or CT Angiography ,is also helpful and typically reveals a hypervascular tumor located between the external and internal carotid arteries.
MRI imaging may also be considered to be the criterion standard of carotid body tumors, and the tumor has a characteristic salt and pepper appearance on T1-weighted image.
TREATMENT is surgical excision taking care of nearby vital structures and to take care internal carotid is preserved through out.patient can be discharged in 1-2 days.