Clinical Data
73-year-old male:
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With worsening paresis of cranial nerves CN3-7
What do you see?
Axial T2 image on the left shows partial obliteration of the right Meckel’s cave and an ill-defined T2 hypointense lesion on the right temporal fossa.
Axial T2 image on the right shows atrophy of the right-sided masticatory muscles.
Post-contrast 3D T1 FSE fat-saturated images showing an enhancing lesion overlying the right temporal fossa, with perineural spread along CN7, the auriculotemporal nerve and continuing intracranially via the right foramen ovale (note the asymmetry in enhancement).
3D bSSFP images (CISS) before (left) and after (right) contrast administration. bSSFP images contain both T1 and T2 information, therefore showing enhancement after contrast administration.
While pre-contrast image doesn’t depict any obvious pathology, the post-contrast image on the right clearly highlights tumor deposits (red arrows) along the lateral aspect of the right cavernous sinus. The tumor has encased the cranial nerves, leading to the patient’s symptoms. For comparison, the normal anatomy of the cranial nerves is shown on the left (green arrows).
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This case shows a histologically verified squamous cell carcinoma of the temporal fossa spreading along the CN7, auriculotemporal nerve, mandibular nerve and into the right cavernous sinus.
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Teaching points:
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Multiple CN palsies of CN3-6 should raise a suspicion of cavernous sinus pathology.
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Auriculotemporal nerve is an important connection between the facial and mandibular nerves.
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bSSFP sequences like CISS contain both T1 and T2 information and therefore show post-contrast enhancement which can be diagnostically useful in conjunction to their excellent spatial resolution.
