Presentation
Follow up study for a known patient with left CPA meningioma.
Patient Data
Left cerebellopontine angel extra-axial dural-based space occupying lesion is noted overlying the left internal auditory canal opening (porus acusticus). It indents and compresses the left aspect of the pons, left middle cerebellar peduncle and left CPA neuronal structures (VII and VIII nerve roots).
It shows minimal extension through the left internal auditory canal. The lesion shows homogeneous low signal on T1, mild hyperintensity on T2, bright signal on FLAIR, no diffusion restriction on DWI, and avid homogeneous enhancement after contrast administration.
It shows large dural tail extending to the clivus to reach the contralateral cerebellopontine angel that could be augmented by the effect of gamma knife radiation therapy.
Case Discussion
The patient came for follow up of a pathologically proved left CPA meningioma managed with gamma knife radiosurgery. The mass lesion remained of the same size as compared to the previous study one year ago.
Schwannomas are more bright on T2 and often have cystic changes if reaches such size. The intracanalicular extension is a constant feature of CPA schwannomas as they arise from inside the canal, however, meningiomas can have intracanalicular extension if reaches large sizes as present in our case.
A dural tail is usually seen with meningiomas, however, it is non-specific and can happen with other extra-axial masses. It is usually smaller than what's seen in this case, so we suggest the added effect of radiation therapy for this dural thickening.