(Ultrasound Review) - This study from the Journal of Ultrasound in Medicine describes the ultrasound characteristics of carotid body tumors in six patients. "Carotid body tumors, also called chemodectomas, are a subtype of extraadrenal paraganglioma," according to the study. "They are slow-growing, usually benign tumors with malignancy occurring in about 6% of tumors."
During carotid artery duplex ultrasound they may be shown splaying the internal carotid artery (ICA) and the external carotid artery (ECA). Surgical removal can be a difficult procedure; the tumors are hypervascular and in close proximity to major vessels.
Patients presented with a swelling or non-tender mass below the angle of the mandible in the antero-lateral aspect of the neck. Ultrasound of the region demonstrated a well-circumscribed, solid, slightly hyperechoic homogenous mass at the carotid bifurcation.
Power Doppler has known advantages over color Doppler for certain situations. Its angle independence and good sensitivity to low flow in small vessels make it the preferred method for these tumors. Using power Doppler, the entire tumor demonstrated a characteristic hypervascular pattern, and pulsed Doppler showed a low resistance waveform.
The size of the lesions ranged from 2-6 cm. Other explanations for this type of swelling include enlarged lymph nodes, aneurysm of the carotid artery, branchial cleft cyst, neurogenic tumor, and salivary gland mass. The defining characteristics for carotid body tumors are location at the bifurcation causing displacement of the ICA and ECA, and the abundant vascular flow on power Doppler.
The researchers conclude that ultrasound incorporating power Doppler is the best imaging modality for these tumors, and that CT, MRI, and digital subtraction angiography (DSA) are not necessary. Ultrasound is inexpensive and noninvasive, and provides the information necessary to make an accurate diagnosis. DSA may be useful for tumor embolization prior to surgery.
J Ultrasound Med 2000; 19:367–370
H Arslan et al
YYU Tip Fakültesi, Radyoloji Anabilim Dah, Maras cad, 65200, Van, Turkey
By Ultrasound Review
September 28, 2000
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