Trigeminal Schwannoma

trigeminal nerve schwannoma

Intracranial schwannomas are relatively common, especially in the setting of neurofibromatosis type 2. Of all intracranial schwannomas, 90% arise from the vestibular nerve (acoustic schwannomas). Half of the remainder (5%) arise from the trigeminal nerve, with all other cranial nerves (except for the olfactory nerve which does not have Schwann cells), making up the remaining 5%.

Typically trigeminal schwannomas have a dumbbell appearance if they extend both in the cisternal compartment and cavernous sinus (as in this case). They can however, if small, be confined to one compartment:

* confined to the cavernous sinus
* confined to Meckel’s cave
* confined to the cisternal compartment (becomes a differential for cerebellopontine angle mass. )

Just as acoustic schwannomas, cystic degeneration is common.

Clinical presentation relates to trigeminal nerve dysfunction: pain, neurasthenia, numbness. If large, then mass effect symptoms may be present.

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2. University of Rochester

Credit: Dr Frank Gaillard