0:01

This was a child that was being evaluated for visual

0:06

field deficits and visual blurring.

0:09

On the MRI of the brain,

0:11

we identified that there was a mass at the foramen

0:15

magnum that was located in an

0:19

intradural extramedullary location. Let's look at this.

0:25

Here we have the mass.

0:27

We can see that it is extramedullary at the

0:29

cervicomedullary junction at the skull base.

0:32

And we see the so-called meniscus sign with

0:35

enlargement of the CSF at the border with the tumor,

0:39

which identifies it as intradural extramedullary.

0:43

On the axial T2-weighted scan,

0:45

we again see the masses separate from the spinal

0:48

cord. So this is our intramedullary compartment,

0:51

but it is within the dural

0:53

thecal sac, so it's intradural extramedullary

0:56

in location, identified here as the bright lesion.

1:01

On our post-gadolinium-enhanced pulse sequences,

1:05

we can see that the abnormality shows contrast

1:09

enhancement. When we look further inferiorly,

1:13

we see that this lesion extends outside the spinal

1:18

canal. So if this is the edge of our dural thecal sac,

1:21

we see that this lesion is extending outside and

1:25

actually is going into the pre vertebral space from

1:30

the neuroforamen at the C1-C2 level.

1:34

I'd like to point out that this lesion has central

1:39

lower signal intensity and a periphery

1:43

of brighter signal intensity.

1:46

And this is our so called target sign.

1:48

If we were to do a sagittal through this,

1:51

we would see as brighter on the periphery and darker

1:55

in the center, the so-called target

1:57

sign of neurofibromatosis, or

2:00

neurofibroma as opposed to a schwannoma.

2:03

And in point of fact,

2:05

this patient has neurofibromatosis type 1,

2:08

and this is what we would call

2:10

a plexiform neurofibroma,

2:13

which is one of the characteristic features

2:15

of neurofibromatosis type 1.

2:18

This patient also had additional lesions in the

2:22

cervical spine. And we're going to move,

2:24

move from the current study to one that's three

2:29

years later after the patient has had resection of

2:33

that cervicomedullary mass. So on this example,

2:39

we can see that on a sagittal and coronal scan,

2:43

that this patient has additional

2:45

lesions in the brachial plexus.

2:49

So this is clearly outside the spinal canal,

2:52

which is here,

2:53

but this is a mass that's associated with

2:56

the brachial plexus on the right side.

3:00

As you notice,

3:00

it has somewhat of a lower signal intensity in the

3:03

center and a periphery of brighter area on the

3:07

T2-weighted scan, so-called target sign

3:10

once again of neurofibroma.

3:13

You'll notice that there's an additional

3:15

one further superiorly here.

3:17

So this patient has neurofibromatosis type 1.

3:20

Let's look at the lumbar spine quickly

3:23

for any additional neurofibromas,

3:25

and we don't see anything of concern here on the

3:30

coronal initial scan and then on the axial scans,

3:36

no additional lesions.

3:38

So it's important to inquire and to investigate the

3:41

entire central nervous system when we're dealing

3:44

with a patient with neurofibromatosis type 1.

3:47

So let's go back to the original question.

3:49

This was a child who had visual field

3:53

problems and visual blurring.

3:55

Remember that neurofibromatosis

3:57

type 1 is associated with

4:00

optic pathway gliomas.

4:02

So if we look back at the patient's optic

4:05

nerves on the scans through the orbits,

4:09

we would be examining it closely for any evidence

4:12

of optic nerve glioma. In this case,

4:15

the patient did not have it.

4:17

So for those of you who are trying to remember this,

4:20

what are the seven major criteria

4:22

of neurofibromatosis type 1?

4:25

Again, we have to do this from memory.

4:26

We have cafe au lait spots. That's one.

4:29

Number two,

4:30

axillary freckling.

4:32

Number three,

4:33

optic pathway glioma.

4:35

Number four,

4:37

a spinal dysplasia,

4:39

sometimes with sphenoid wing dysplasia.

4:43

We have number five,

4:47

family member with neurofibromatosis type 1.

4:50

Number six, plexiform neurofibroma.

4:53

And number seven, lisch nodules,

4:56

which are identified in the globes.

4:59

So this was indeed a case of neurofibromatosis type 1

5:02

with multiple neurofibromas in the intradural

5:05

extramedullary, as well as extradural space,

5:09

as well as in the brachial plexus.