QUIZ: No. 18, 24/05/2026

Diagnosis: Vagal Schwannoma

Findings:

A well-defined oval encapsulated mass lesion is noted in the left carotid space. The lesion appears mildly hypoattenuating on non-contrast CT with mild heterogeneous arterial enhancement and progressive enhancement on venous phase imaging. The lesion causes characteristic separation of the common carotid artery anteromedially and internal jugular vein posterolaterally without vascular encasement. No internal calcification, necrosis, or flow voids are seen.

Discussion

·  Vagal schwannoma is a benign nerve sheath tumor arising from the vagus nerve within the carotid sheath from the vagus nerve located between carotid artery and internal jugular vein.

·  Imaging typically demonstrates a well-circumscribed carotid space mass with separation of the carotid artery and internal jugular vein, which helps distinguish it from sympathetic chain schwannoma and carotid body paraganglioma.

·  Delayed progressive enhancement and absence of marked hypervascularity favor schwannoma over paraganglioma.

Teaching pearl:

Separation of the carotid artery and internal jugular vein is a characteristic imaging feature of vagal schwannoma.