The patient presented to the opthalmologist with a history of acute blindness. Clinical examination revealed left-sided optic atrophy and no other significant findings.

The CT brain study had a few technical issues. It was acquired on a bony protocol and hence appears grainy. The CT contrast administration was suboptimal too, one would have expected a much more avid enhancement post-contrast administration, especially in view of the MRI findings suggesting a meningioma. This also prevented the confident exclusion of an intracranial aneurysm on the post-contrast CT study.

Multiplanar and multiaxial MRI brain confirmed the left planum sphenoidale meningioma with optic nerve and optic chiasm involvement. A primary left optic nerve or optic chiasmatic meningioma and regional spread cannot be definitively excluded. However, there is a normal optic foramen and no intraorbital extension is present.

The sphenoid wing is normal rather than hyperostotic on both CT and MRI studies and suggests a sphenoid wing meningioma is possible but less likely. A posterior olfactory groove meningioma is also part of the differential and can be difficult to exclude especially if a large meningioma is detected at the time of presentation.