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This is a patient with neurofibromatosis type 2

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that we separately discussed the evolution of

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vestibular schwannomas from

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this incidental finding in the left internal

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auditory canal to growing larger to very

0:14

large and subsequent surgical resection.

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Now, beyond these vestibular schwannomas,

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there's a variety of other intracranial

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manifestations that are important to discuss.

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We've discussed that neurofibromatosis

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type 2 can also be thought of as MISME

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syndrome, multiple inherited schwannomas,

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meningiomas, and appendomas.

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Well, what does that look like?

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Well, if we look on this image here, in addition

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to these bilateral vestibular schwannomas, if

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we go posteriorly, we see this enhancing lesion

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off the inferior aspect of the cerebellum.

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That's a meningioma.

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If we scroll superiorly, we see

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this intraventricular lesion in the

1:05

atrium of the left lateral ventricle.

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This is an intraventricular meningioma.

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If we go superiorly, you end up

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seeing multiple small lesions.

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This lesion right here is a meningioma.

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This lesion right here adjacent to the superior

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sagittal sinus near the vertex is a meningioma.

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There's multiple additional smaller ones.

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This one here is a meningioma that can

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be almost mistaken for a cortical vein,

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but this is actually a meningioma.

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So there's multiple additional findings.

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This here is a meningioma that was actually

1:50

previously partially resected and is actually a

1:54

partial extension into the left frontal sinus.

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So there's multiple different meningiomas,

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including this here around the superior

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sagittal sinus, the posterior third

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of the superior sagittal sinus.

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Which we can see best on this diffusion weighted

2:12

imaging showing this near encasement of the

2:17

superior sagittal sinus from this meningioma.

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And because the meningioma is so visible

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on diffusion-weighted imaging, there's a

2:27

reasonable likelihood that it is an atypical

2:29

or potentially high-grade meningioma.

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What else do we see in this patient?

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Well, here is a left

2:40

oculomotor nerve schwannoma.

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Here is a focal protrusion along the

2:46

lateral aspect of the left cavernous sinus.

2:49

Which very well could be a meningioma

2:52

with knowledge that the super lateral

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margin of the left cavernous sinus is

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where the oculomotor nerve enters, and

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immediately caudal to that is where the

3:05

fourth nerve, the trochlear nerve enters.

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The abducens nerve or cranial nerve

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six goes through the cavernous sinus.

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But this seems to be separate from

3:17

this oculomotor nerve schwannoma.

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And I do not see it fully filling

3:22

and effacing the oculomotor cistern.

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So this very well could be a meningioma.

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So there's a variety of manifestations of this.

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Now this patient previously had had a lesion in

3:39

the left temporal pole that had been resected.

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That was a rare manifestation known as meningio

3:45

angiomatosis that involves and invaded the left

3:50

temporal lobe and was the source of seizures.

3:53

And so that is actually something that.

3:57

Initially, what brought this patient to

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medical attention, and it was only later that

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the vestibular schwannomas were identified.

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So there's a wide variety

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of intracranial findings.

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Now, as I mentioned, there's the term, multiple

4:13

inherited schwannomas, which we have the very

4:16

least these two large bilateral vestibular

4:17

schwannomas and the left oculomotor schwannoma.

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meningiomas, we saw multiple meningiomas,

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including this intraventricular

4:24

meningioma, and this Tentorial meningioma.

4:28

But the other part of MISB

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syndrome is appendomoma.

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And if we look at this spine imaging, we

4:33

see a focal enlargement of the mid to upper

4:36

cervical cord with central T2 hyperintense

4:39

signal and post-contrast enhancement.

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In the setting of neurofibromatosis type 2, this

4:45

is consistent with a spinal cord ependymoma.

4:49

Now on this, we also see this large lesion.

4:53

Intradural extramedullary that

4:55

extends through and expands this

4:58

neural foramen, this is a schwannoma.

5:01

Now, in these patients we often will

5:04

see other little enhancing lesions.

5:06

So there's multiple additional

5:08

intradural enhancing lesions.

5:10

Those are likely all small schwannomas.

5:13

Now, because this is a genetic

5:15

defect in neurofibromatosis type 2,

5:19

a genetic abnormality, these are not

5:22

considered to be metastatic deposits.

5:24

This is considered to be multicentric disease.

5:27

Multicentric disease means each one of these

5:30

lesions is a separately derived tumor that came

5:35

about because of the germline mutation within

5:38

chromosome 22 for neurofibromatosis type 2.

5:42

So this patient has all the characteristic

5:44

findings of neurofibromatosis type 2.

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We have multiple schwannomas,

5:49

both intracranial and spinal.

5:51

We have multiple meningiomas, and

5:54

we have a spinal cord ependymoma.

5:56

This shows that even though neurofibromatosis

5:58

type 2 is not the most common disease

6:01

process in the general population, These

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patients end up having frequent contact

6:06

with the healthcare system, frequent medical

6:10

imaging, and so it is not uncommon to

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see follow-up studies on these patients.

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I have several neurofibromatosis type 2

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patients that between brain, spine, and various

6:22

other body parts have well over 50 to 100.

6:26

different MR examinations in their past.

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So it's very common to see imaging on these,

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even more common than you would expect based

6:35

upon the disease prevalence in the population.