Head and Neck #3 – Long Case

Axial STIR

Axial T1

Where is the lesion?

Situated at the left common carotid artery bifurcation.

What is the lesion like?

Enhancing soft tissue tumor splaying the internal and external carotid arteries.

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Axial STIR

Axial T1

What MRI signal characteristics shows the lesion?

Hyperintense on the STIR with dark foci giving salt and pepper appearance. Hypointense on T1.

What is the differential diagnosis?

Carotid body tumor: glomus tumor or paraganglioma of the carotid body. It characteristically splays the internal and external carotid arteries.
Vagal schwannoma: tends to displace both arteries together to one side.
Glomus vagale: paraganglioma with the same signal characteristics as the carotid body paraganglioma but is located more superiorly at the skull base and may extend into the jugular foramen.

What is the most likely diagnosis?

Diagnosis: Carotid body tumor.

Head and Neck – Flashcard #2

What do you see on the following images?

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Dehiscent jugular bulb

The jugular bulb bulges into the left middle ear cavity with absence of the sigmoid plate separating the jugular bulb from the middle ear in keeping with dehiscent jugular bulb.

It is one of the causes of pulsatile tinnitus, patients can also present with conductive hearing loss if the jugular vein contacts the tympanic membrane.

Head and Neck – Flashcard #1

Axial CT bone window

What do you see on this image?

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Otosclerosis

There is a small lucency anterior to the vestibule, just lateral to the basal turn of the cochlea. Consistent with fenestral otosclerosis.

There are two types of otosclerosis:

1- Fenestral: is the most common type. It involves the bone anterior to the oval window and causes conductive hearing loss.
2- Retro-fenestral: involves the cochlear capsule and causes sensorineural hearing loss.
The two types can occur simultaneously.