Neuroradiology Case of the Month

May 2002

Manoj Ketkar, MD, Henry Wang, MD, PhD and P.L. Westesson, MD, PhD, DDS

Clinical Presentation: A 54-year-old lady was referred with symptoms of dysphagia. There was a palpable mass on the right side of her neck.

Neck MRI Findings: A large mass was noted in the right carotid space, which was hyperintense on T2-weighted images and enhanced strongly after administration of intravenous contrast (Fig. 1A). A similar smaller mass was noted in the region of the left jugular foramen (Fig. 1B). Due to characteristic location and strong enhancement after administration of intravenous contrast, diagnosis of paraganglioma was made. The patient was referred to us for pre-operative embolization.

Angiogram Findings: The right common carotid angiogram revealed a large vascular mass starting from the carotid bifurcation extending up to the skull base on the right side displacing the right internal carotid artery anteriorly and medially. The selective right external carotid artery angiogram revealed an enlarged posterior auricular artery mainly supplying this vascular mass (Fig. 2A&B). There was no supply from right internal carotid artery. Embolization was carried out using embolospheres (300-500 microns) via a microcatherer put selectively into the enlarged posterior auricular artery (Fig. 3A). The check angiogram revealed significant reduction in the vascularity of the tumor with a small blush noted near the carotid bifurcation (Fig. 3B). A large mass was removed at surgery, which was adherent to the 10th and 12th cranial nerves (Fig. 4). There was no significant blood loss at the surgery due to pre-operative embolization.

Diagnosis: Right carotid space paraganglioma, glomus vagale.

Figure 1 (A & B): MRI of neck demonstrates an enhancing mass in the right carotid space and base of the skull on the left side (arrows), consistent with paragangliomas.

Figure 2 (A &B): Right common carotid angiogram demonstrates a lerge vascular mass. The selective external carotid angiogram reveals an enlarged posterior auricular artery (arrow).
Figure 3 (A & B): Angiogram through the microcatheter demonstrates significant reduction in the vascularity of the tumor. A small blush of contrast (arrow) is noted near the carotid bifurcation.
Figure 4: The right Glomus Vagale tumor removed after the surgery.

Discussion: Paragangliomas are slowly enlarging masses. These are benign tumors which arise from the neural crest paraganglion cells. There are multiple in 3-5% of the cases and those with family history, the incidence of multiplicity goes up to 20-30% [1].

Imaging Findings: CT scans reveal an intensely enhancing mass in the carotid space. On MRI there is characteristic salt and pepper appearance due to the flow (pepper) and hyperintensity due to hemorrhage (salt).

Depending on the location of the paraganglioma, the tumors are named as carotid body tumor, glomus vagale, glomus jugulare, glomus tympanicum [1].

In our case, there was glomus vaglae on right side and glomus typanicum on the left side. When paraganglioma is identified a search for other paraganglioma should be carried out [1].

Acknowledgement: Authors wish to thank Belinda DeLibero and Margaret Kowaluk for their help in preparing this case of the month.

References:

1. Som P, Curtin H. Head and Neck Imaging. Third Edition, 932-936, Mosby- Year book Inc., St. Louis, Missouri.