Presentation
Left trigeminal neuralgia.
Patient Data
The MRI sequences demonstrate an extra-axial dural-based mass (20 x 18 x 16 mm) of the left cerebellopontine angle located above the internal auditory canal (IAC) in contact with the anteromedial margin of the tentorium cerebelli with a mass effect on the cisternal segment of the ipsilateral trigeminal nerve and middle cerebellar peduncle. It shows an isosignal to the cortical grey matter on T1, T2, and FLAIR with a central area of low signal on all sequences (calcification). The postcontrast sequences show a vivid homogeneous enhancement of the non-calcified component.
No significant mass effect on the ipsilateral VII and VIII cranial nerves.
Case Discussion
MRI features are most consistent with a CPA meningioma compressing the cisternal segment of the left trigeminal nerve.
On imaging, the main differential diagnoses are acoustic schwannoma and trigeminal schwannoma.