carotid body tumors ( cbt ) are rare chemical receptor tumors which accounts for 0.6% of the head and neck tumors in human .
although surgical resection is a reliable therapeutic method for cbt , the procedure is technically challenge for surgeons due to the tumor 's adjacent to great vessels and cranial nerve .
we report nine cases of cbt who were treated at our center during 2004 to 2008 with a literature review .
from 2004 to 2008 , nine patients were diagnosed as cbt at the department of vascular surgery , xuanwu hospital , capital medical university . among them , five were male , the mean age was 43 years ( range from 26 to 84 years ) .
low echo - level chunks were detected in external carotid arteries and internal carotid arteries .
seven patients underwent transcranial doppler ( tcd ) sonography before the surgery ( figure 2 ) . in all of these patients ,
the carotid artery compression test showed that blood flow in cerebral arteries decreased by 60% or more .
three patients had ct examination with angiography plus three - dimensional reconstruction , which showed that soft tissues encased the posterior lateral side of the left common carotid artery bulb .
all patients had digital subtraction angiography ( dsa ) , which showed abnormal accumulation of contrast medium at the crotch of common carotid artery .
four patients were classified as type i , two as type ii and three as type iii .
four of them underwent simple carotid body tumor resection , two underwent carotid body tumor resection and ligation of external carotid artery and two had common carotid artery - internal carotid artery artificial vascular reconstruction .
no perioperative mortality and stroke occurred . during a mean follow - up of 2.2 years ( 3 months to 6 years )
, the patient who refused surgery died three years after the diagnosis due to complications from bone fracture .
the patient with malignant tumor died two years after the surgery due to multiple metastases .
cbt is the most frequently diagnosed carotid body disease and is also termed as chemodectoma .
it is originated from nervous crest and belongs to nonchromaffin paraganglioma , which is similar to chromaffin suprarenal medulla tumors ( such as chromaffin tumors ) with the same origin in histology .
cbt can be found at any age and is frequently seen in those between 50 and 70 years old , which slightly higher prevalence in women than men .
bilateral disease is significantly more frequent in familial ( 31.8% of cases ) than in non - familial cbt ( 4.4% ) .
the blood supply of cbt is abundant , which is mainly from external carotid artery and branches .
blood supplies from internal carotid artery , vertebral artery , ascending pharyngeal artery and superior thyroid artery have also been reported .
in addition to external carotid artery , multiple blood supply from internal carotid artery , thyrocervical trunk , vertebral artery and ascending pharyngeal artery were also found in two patients in our case series .
color doppler ultrasound , a simple and non - invasive examination , has relatively high specificity and sensitivity for cbt .
other diagnostic methods include aspiration - needle biopsy , ct and mri . the accuracy of mri is higher in comparison to that of ct . furthermore , mri is not radioactive , and the diagnostic rate for multiple lesions is particularly important for the patients with family history .
shamblin research group classified cbt into type i ( localized type ) , type ii ( partially wrapped type ) and type iii ( wrapped type ) . with the higher shamblin grading ,
the possibilities for injuries in cranial nerves , fragility of cervical great vessels are higher during or after operations .
recent advance in vascular imaging techniques have enabled preoperative grading for tumor size , which can be completely consistent with the shamblin grading during operations .
, we have divided the surgery into four types according to shamblin grading and tumor blood supply .
simple resection of carotid body tumor is the most ideal operation form , which would not damage the shape and distribution of cervical arteries .
thus , it is suitable for shamblin type i / ii cases without abundant blood supply .
carotid body tumor resection and reconstructive vascular operation ( including simple vascular anastomosis , internal carotid artery - common carotid artery artificial and autologous reconstructive vascular operation ) are suitable for shamblin type iii cases with enormous tumors and malignant tumors involving important peripheral vessels . in the carotid body tumor resection and ligation of common carotid artery ,
cerebral ischemia is a relatively common complication and now is only used for emergent treatments .
medullary chromaffinoma is always benign and the incidence of malignant tumors is lower than 10% .
one case of malignant cbt in our patients had vertebral body metastasis two years after resection and finally died of the disease .
hu et al . summarized 967 patients in 36 centers from 1962 to 2001 and reported that radiotherapy can be used as the adjunctive therapy for primary and metastatic foci .
the efficacy for local control was equal to that for operations and the incidence of complications was significantly reduced in comparison to that for operations .
however , results from prospective studies of radiotherapy for malignant cbt are still unavailable and it is not routinely .
color doppler ultrasound , a simple and non - invasive examination , has relatively high specificity and sensitivity for cbt .
other diagnostic methods include aspiration - needle biopsy , ct and mri . the accuracy of mri is higher in comparison to that of ct .
furthermore , mri is not radioactive , and the diagnostic rate for multiple lesions is particularly important for the patients with family history .
shamblin research group classified cbt into type i ( localized type ) , type ii ( partially wrapped type ) and type iii ( wrapped type ) . with the higher shamblin grading ,
the possibilities for injuries in cranial nerves , fragility of cervical great vessels are higher during or after operations .
recent advance in vascular imaging techniques have enabled preoperative grading for tumor size , which can be completely consistent with the shamblin grading during operations .
, we have divided the surgery into four types according to shamblin grading and tumor blood supply .
simple resection of carotid body tumor is the most ideal operation form , which would not damage the shape and distribution of cervical arteries .
thus , it is suitable for shamblin type i / ii cases without abundant blood supply . carotid body tumor resection and reconstructive vascular operation ( including simple vascular anastomosis , internal carotid artery - common carotid artery artificial and autologous reconstructive vascular operation )
are suitable for shamblin type iii cases with enormous tumors and malignant tumors involving important peripheral vessels . in the carotid body tumor resection and ligation of common carotid artery ,
cerebral ischemia is a relatively common complication and now is only used for emergent treatments .
medullary chromaffinoma is always benign and the incidence of malignant tumors is lower than 10% .
one case of malignant cbt in our patients had vertebral body metastasis two years after resection and finally died of the disease .
hu et al . summarized 967 patients in 36 centers from 1962 to 2001 and reported that radiotherapy can be used as the adjunctive therapy for primary and metastatic foci .
the efficacy for local control was equal to that for operations and the incidence of complications was significantly reduced in comparison to that for operations .
however , results from prospective studies of radiotherapy for malignant cbt are still unavailable and it is not routinely .
 carotid body tumors ( cbt ) are rare chemical receptor tumors . 
 we report nine cases of cbt who were diagnosed at our center during 2004 to 2008 with a literature review . of these nine patients , 
 eight underwent complete resection , one received palliative resection due to the malignant nature of the tumor , and the other one refused surgery . 
 no perioperative mortality and stroke occurred . during a mean 
 follow up of 2.2 years , no deaths related to cbt occurred . 
 surgical treatment for cbt is relatively safe 
 . the surgeon should be careful to maintain the integrity of carotid artery , and prevent cerebral ischemia and cranial nerve injuries in order to improve outcome . 
Introduction
Case report
Discussion
Clinical diagnosis for CBT
Surgical treatment of CBT
Malignant CBT