Vascular Techniques Exam 3 Practice

A mass located between the internal and external carotid arteries at the bifurcation is most consistent with a carotid body tumor. This lesion arises from the glomus (paraganglionic) cells right at the carotid body at the bifurcation, so it sits precisely between the two arteries. A hallmark imaging feature is that it tends to push (splay) the ICA and ECA apart, a sign often described as the splaying or Lyre sign. Its size is commonly in the range of 1–6 cm, which fits the description given. These tumors are typically highly vascular, receiving feeders from branches of the external carotid artery, which helps explain why Doppler or angiography shows a prominent vascular blush. This localization and vascular pattern help distinguish carotid body tumors from other possibilities: an aneurysm would arise from the vessel wall itself, a lymph node would lie along nodal pathways rather than sandwiched between the two arteries, and an atherosclerotic plaque is intraluminal within an artery rather than a discrete mass between them.