Carotid body tumors.

Abstract

C Also known as cervical paragangliomas, these neoplasms are of the neuroectodermal paraganglion cells. Originating from the afferent ganglion of the glossopharyngeal nerve, carotid body tumors are generally located at the carotid bifurcation. These tumors carry more blood flow per gram than any other tumor. The primary blood supply is from the external carotid artery and its branches. The most common presentation is the development of an asymptomatic anterior neck mass without a thrill or bruit. Cranial nerve deficits are uncommon, but may be seen in patients with masses greater than 5 cm in size. CT scanning with contrast is the imaging modality of choice to define the size of the tumor (A). In addition, it can identify contralateral tumors. Using the CT scan, the Shamblin type of the tumor is identified. (B, Type I: small tumor, easily resectable; Type II: large tumor, adherent to the vessels; Type III: tumor surrounding the internal carotid artery, may encase nerves.) Contrast angiography generally shows a highly vascular mass at the carotid bifurcation (C). Test occlusion of the common carotid artery during angiography may predict the need for carotid shunting should carotid clamping be necessary during the resection.