Interactive Transcript
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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
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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
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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
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previously partially resected and is actually a
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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
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imaging showing this near encasement of the
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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
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reasonable likelihood that it is an atypical
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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
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oculomotor nerve schwannoma.
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Here is a focal protrusion along the
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lateral aspect of the left cavernous sinus.
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Which very well could be a meningioma
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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
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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
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this oculomotor nerve schwannoma.
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And I do not see it fully filling
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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
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the left temporal pole that had been resected.
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That was a rare manifestation known as meningio
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angiomatosis that involves and invaded the left
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temporal lobe and was the source of seizures.
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And so that is actually something that.
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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
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inherited schwannomas, which we have the very
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least these two large bilateral vestibular
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schwannomas and the left oculomotor schwannoma.
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meningiomas, we saw multiple meningiomas,
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including this intraventricular
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meningioma, and this Tentorial meningioma.
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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
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see a focal enlargement of the mid to upper
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cervical cord with central T2 hyperintense
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signal and post-contrast enhancement.
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In the setting of neurofibromatosis type 2, this
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is consistent with a spinal cord ependymoma.
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Now on this, we also see this large lesion.
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Intradural extramedullary that
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extends through and expands this
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neural foramen, this is a schwannoma.
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Now, in these patients we often will
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see other little enhancing lesions.
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So there's multiple additional
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intradural enhancing lesions.
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Those are likely all small schwannomas.
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Now, because this is a genetic
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defect in neurofibromatosis type 2,
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a genetic abnormality, these are not
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considered to be metastatic deposits.
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This is considered to be multicentric disease.
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Multicentric disease means each one of these
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lesions is a separately derived tumor that came
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about because of the germline mutation within
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chromosome 22 for neurofibromatosis type 2.
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So this patient has all the characteristic
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findings of neurofibromatosis type 2.
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We have multiple schwannomas,
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both intracranial and spinal.
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We have multiple meningiomas, and
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we have a spinal cord ependymoma.
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This shows that even though neurofibromatosis
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type 2 is not the most common disease
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process in the general population, These
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patients end up having frequent contact
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with the healthcare system, frequent medical
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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
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other body parts have well over 50 to 100.
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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
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upon the disease prevalence in the population.
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