title: CT AND MRI FEATURES OF CAROTID BODY PARAGANGLIOMAS IN 16 DOGS.
abstract: Carotid body tumors (paragangliomas) arise from chemoreceptors located at the carotid bifurcation. In imaging studies, this neoplasm may be confused with other neck neoplasms such as thyroid carcinoma. The purpose of this retrospective, cross-sectional study was to describe computed tomographic (CT) and magnetic resonance imaging (MRI) characteristics of confirmed carotid body tumors in a multi-institutional sample of dogs. A total of 16 dogs met inclusion criteria (14 examined using CT and two with MRI). The most common reason for imaging was a palpable cervical mass or respiratory signs (i.e., dyspnea or increased respiratory noises). The most commonly affected breed was Boston terrier (n = 5). Dogs were predominantly male castrated (n = 10) and the median age was 9 years [range 3-14.5]. Most tumors appeared as a large mass centered at the carotid bifurcation, with poor margination in six dogs and discrete margins in ten dogs. Masses were iso- to hypoattenuating to adjacent muscles in CT images and hyperintense to muscles in T1- and T2-weighted MRI. For both CT and MRI, masses typically showed strong and heterogeneous contrast enhancement. There was invasion into the adjacent structures in 9/16 dogs. In six of these nine dogs, the basilar portion of the skull was affected. The external carotid artery was entrapped in seven dogs. There was invasion into the internal jugular vein in three dogs, and into the external jugular, maxillary, and linguo-facial veins in one dog. Imaging characteristics helped explain some clinical presentations such as breathing difficulties, Horner's syndrome, head tilt, or facial nerve paralysis.
authors.affiliation: Department of Clinical Studies, Section of Radiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA, 19104.
authors.forename: Wilfried
authors.initials: W
authors.lastname: Mai
authors.affiliation: Department of Molecular Biomedical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, NC, 27607.
authors.forename: Gabriela S
authors.initials: GS
authors.lastname: Seiler
authors.affiliation: William H. Pritchard Veterinary Medical Teaching Hospital, University of California-Davis, Davis, CA, 95616.
authors.forename: Britany J
authors.initials: BJ
authors.lastname: Lindl-Bylicki
authors.affiliation: Department of Surgical and Radiological Sciences, University of California-Davis, Davis, CA, 95616.
authors.forename: Allison L
authors.initials: AL
authors.lastname: Zwingenberger
mesh_terms: D000818:Animals; D002339:Carotid Arteries / Q000000981:diagnostic imaging / Q000473:pathology; D002345:Carotid Body Tumor / Q000662:veterinary*; D003287:Contrast Media; D003430:Cross-Sectional Studies; D003937:Diagnosis, Differential; D004283:Dog Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging; D004285:Dogs; D004417:Dyspnea / Q000662:veterinary; D005260:Female; D006258:Head and Neck Neoplasms / Q000662:veterinary; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000662:veterinary*; D008297:Male; D009361:Neoplasm Invasiveness; D011856:Radiographic Image Enhancement / Q000379:methods; D012189:Retrospective Studies; D013964:Thyroid Neoplasms / Q000662:veterinary; D014057:Tomography, X-Ray Computed / Q000662:veterinary*
chemical_list: D003287:Contrast Media
keywords: CT; MRI; carotid body tumor; chemodectoma; dog; paraganglioma