|Case 6 :|
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Findings reveal bilateral
hyperdense enhancing mass lesions with feeder vessels, at the carotid
are tumors that arise from the branchiomeric paraganglia which are
distributed from the skull base down to the aortic arch. These neoplasms
are most commonly seen arising from the carotid body, the paraganglionic
tissue located at the carotid bifurcation. Although these tumors were
originally termed chemodectomas, the term carotid body tumor (CBT) has
emerged as the most popular description for those located at the carotid
Other common sites for paragangliomas to arise are from the paraganglia of the tympanic, jugular, and the high vagal regions. The nomenclature most commonly used for these tumors are glomus tympanicum, glomus jugulare, and glomus vagale.
differential diagnosis of an incidentally observed non-tender antero-lateral
neck mass includes metastatic lymph nodes, carotid body aneurysm, salivary
gland tumor, branchial cleft cyst, and thyroid and neurogenic tumors.
Although arteriography is considered mandatory and remains the gold
standard for diagnosis, noninvasive imaging studies are frequently
adequate for workup of suspected CBTs.
demonstrates a solid mass that shows homogenous enhancement on
intravenous contrast administration. The presence of uniform contrast
enhancement and large feeding vessels into the tumor is not seen in lymph
node masses and schwannomas. The incorporation of large feeding vessels is
typical of carotid body paragangliomas whereas schwannomas tend to
displace the adjacent vessels. The medical displacement of the internal
carotid artery is considered to be specific for tumors of vagal origin,
whether they are schwannomas or paragangliomas
the gold standard for
diagnosing CBTs, this study demonstrates a pathognomonic tumor blush as
well as the feeding vessels of the tumor; and is an excellent screening
tool for concomitant paragangliomas.
non-contrast T1W images demonstrate a heterogeneous mass with isointense
signal intensity at the carotid artery bifurcation with multiple
serpentine areas of low signal intensity representing flow voids
throughout the mass. On T2W images the tumor shows hyperintense signal
intensity. On intravenous gadolinium DTPA contrast administration, the
tumor enhances intensely.