Case 5

I am presented with an MRI brain study of a young child; the salient finding is tubular or fusiform enlargement of the right optic nerve. I also note kinking or buckling of the enlarged optic nerve. It shows high T2 signal and intermediate T1 signal. 

There is moderate to avid post contrast enhancement on the post gadolinium series, which appears homogeneous and based on the centre of the nerve.

I note that there is no calcification.

The features are characteristic of an optic nerve glioma.

The main differential diagnosis would be an optic nerve sheath meningioma; these can be differentiated by their features- they arise peripherally and therefore the enhancement would be peripheral, showing a ‘tram track’ appearance on the axial series. They also commonly exhibit calcifications.

I would inform the referring physician of the findings and raise this case for discussion at neurology MDT.