Interactive Transcript
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This is a 16-year-old
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with no neurofibromatosis type 2.
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We see bilateral vestibular schwannomas
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where there is filling and expansion
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of the internal auditory canals,
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expansion of the porous acusticus,
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more on the right,
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and a component of the lesion that extends
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into the cerebellar pontine angle cistern
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and results in mass effect upon
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the brainstem and the lateral aspect
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of the middle cerebellar peduncles.
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So, we look closely at the rest of the study,
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we see there is an enhancing lesion
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in the right cavernous sinus.
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What is this?
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Well, there's more than one possibility.
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So, neurofibromatosis type 2.
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We tend to think of as being bilateral
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vestibular schwannomas,
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but they can have schwannomas of
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multiple other cranial nerves,
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and it's known that cranial nerves three
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and four are associated with the lateral
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aspect of the cavernous sinus
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and cranial nerve six, the abducens nerve,
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goes through the cavernous sinus,
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but this doesn't look exactly like
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I would typically expect a schwannoma to look.
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So, neurofibromatosis type 2 also has
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association with other lesions.
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In particular, intracranial meningiomas.
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And this looks very much like what
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we would expect a cavernous sinus
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meningioma to look like.
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So, while we do not have histologic confirmation,
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it's very possible this is a cavernous sinus meningioma.
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Neurofibromatosis type 2 patients also
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get intramedullary spinal cord ependymomas.
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So, while the name is neurofibromatosis type 2,
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there is a name that has been proposed
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of multiple inherited schwannomas,
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meningiomas, and ependymomas.
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M-I-S-M-E, or MISME.
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Now, most people and most of the literature
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will still know it and refer to it
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as neurofibromatosis type 2.
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So, it's important to use that terminology.
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But the MISME syndrome,
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or multiple inherited schwannomas,
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meningiomas, and ependymomas,
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it's important to be aware of that
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because to be on the lookout for
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meningiomas and other findings.
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Now, this patient also,
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we see this lesion in the anterior
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aspect of the left optic nerve sheath.
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If we look on this coronal T1 post contrast image
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and this coronal STIR image,
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we're seeing some expansion there.
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That's a little bit puzzling and that's
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admittedly not a characteristic finding
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of neurofibromatosis type 2,
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but it is something that warrants surveillance.
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It also warrants genetic evaluation
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for other entities because, again,
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this is not explained by the typical
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findings of neurofibromatosis type 2.
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So, it shows that beyond the characteristic findings
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of a given entity,
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we have to be on the lookout for other things
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that the patient may have.
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So, this patient has neurofibromatosis type 2
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with bilateral vestibular schwannomas,
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a right cavernous sinus lesion,
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presumably meningioma,
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and a left optic nerve sheath lesion
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of unknown etiology, at this point.
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