Presentation
Right sided facial pain, headache, seizure, ataxia and right ophthalmoplegia.
Patient Data
A large dumbbell-shaped heterogeneous mass is seen in the right cerebellopontine angle extending anteriorly along the course of the right trigeminal nerve into the right Meckel's cave and right lateral part of the cavernous sinus. The mass predominantly consists of cystic components which are hypointense in T1WI, and hyperintense in T2WI. In FLAIR these areas show signal attenuation. Nodular solid components are seen within the cystic areas which are isointense in T1WI and T2WI sequences. In post-contrast images, the solid components show moderate enhancement. The cystic components show facilitated diffusion whereas the solid components exhibit mild diffusion restriction.
Significant mass effect is exerted by mass over the brainstem and 4th ventricle. The brainstem is displaced to the left side. The right internal carotid artery and right optic nerve are compressed and displaced by the mass. The right medial temporal lobe and right temporal horn are compressed by the mass.
Impression: Imaging features are consistent with right sided trigeminal schwannoma.
Case Discussion
The trigeminal schwannomas are rare and benign intracranial tumors which account for 1-2% of all intracranial schwannomas. They are more common in middle aged females and have a slow insidious course. They most commonly arise from the cisternal segment and tend to grow along the course of the trigeminal nerve.