Glomus Jugulare

Glomus jugulare are benign, slow-growing paragangliomas that can arise from 3 bodies around the jugular foramen: The jugular bulb, the tympanic branch of cranial nerve IX (Jacobsen nerve) and the auricular branch of cranial nerve X (Arnold nerve).

CT may reveal a "permeative-destructive" change of adjacent bone (green arrow). Contrast-enhanced CT images will reveal homogeneous intense enhancement (pink arrow). on MRI, the "salt and pepper" appearance on T1-weighted images is typical with the white dots of salt representing hemorrhage or slow flow in vessels and black dots of pepper representing high velocity flow voids from feeding arterial branches. T2-weighted images reveal a heterogeneously hyperintense mass with hypointense foci.

Important considerations include extension to adjacent spaces, most commonly the middle ear, which was clear in this case (yellow arrow). Signs of compression of the neural contents of the jugular foramen (cranial nerves IX, X, and XI) should also be sought. In this case, medial deviation of the left vocal fold (blue arrow) is due to mass effect on the vagus nerve. The left sternocleidomastoid muscle is a bit smaller than the right, possibly reflecting injury to the spinal accessory nerve.

Differential considerations for a jugular foramen mass include:

• Meningioma: Permeative-sclerotic pattern of the adjacent bone with an enhancing dural tail.
• Schwannoma: Relatively uncommon. Usually arise from cranial nerve 9. May cause smooth remodeling and enlargement of the jugular foramen.
• Metastases: