0:00

So we say that nerve sheath tumors are the most common

0:04

of the intradural extramedullary neoplasms.

0:08

Number two would be meningioma.

0:11

Meningiomas tend to prefer the thoracic region

0:14

over the cervical and lumbar region.

0:17

And in the thoracic region, they would be the most common

0:20

of the intradural extramedullary neoplasms.

0:23

Occasionally, you will have a meningioma which extends

0:26

beyond the dural surface and grows into, for example,

0:30

the neural foramen or the paraspinal soft tissues.

0:33

So rarely, you will have combined intradural

0:37

as well as extradural meningiomas.

0:40

The demographics of meningiomas are the same

0:43

demographics of meningiomas intracranially, and that is

0:46

that it is more common in women and it peaks

0:50

at about the age forties to fifties.

0:53

Typical features of meningiomas,

0:56

they are typically isointense to the spinal cord on

0:59

both T1-weighted, as well as T2-weighted scans.

1:02

And then they have the broad attachment to the dura

1:06

which may lead to what is referred to

1:09

as the dural tail of enhancement.

1:12

So if we draw the dura here in a sagittal scan,

1:16

so this is anterior and this is posterior,

1:19

what we see with meningiomas is the

1:23

intradural extramedullary mass.

1:26

We'll draw the spinal cord being displaced

1:28

here, with the so-called meniscus sign.

1:31

But as opposed to the neurofibromas or schwannomas,

1:37

one might expect to see a little bit of an enhancing

1:40

dural tail associated with a meningioma.

1:44

So all this is going to enhance and then you'll have

1:46

these trailing off little tails of the dural

1:49

enhancement, the so called dural tail,

1:52

which is characteristic of a meningioma.

1:56

As opposed to neurofibromas or schwannomas,

1:58

meningiomas have the highest rate of calcification of

2:01

intradural extramedullary lesions and they may also lead

2:05

to bone reaction, be it hyperostosis or lysis.

2:10

This is to be distinguished from nerve sheath tumors,

2:13

which generally enlarge foramina or remodel

2:16

it without a lytic or hyperostotic border.

2:20

This is a CT scan of the cervical spine and we

2:24

see a lesion which has hyperdense components.

2:28

So just as intracranially on a non-contrast scan, where

2:33

the most common hyperdense extra axial mass is going to

2:37

be a meningioma. Here we have one in the cervical spine

2:41

where we have a hyperdense mass which has a focus of

2:45

calcification with it, and the spinal cord

2:48

is being displaced to the right side.

2:51

So this would be a characteristic

2:53

feature of a meningioma.

2:56

Little bit surprised that this is also going into

3:00

the neural foramen.

3:01

So this is one that is going both from an intradural

3:04

location to an extradural location, a meningioma.

3:08

Here we have post-gadolinium-enhanced images of the

3:11

cervical spine in the sagittal and axial plane.

3:15

You'll notice that there is a mass which is displacing the

3:18

spinal cord posteriorly and is showing contrast

3:21

enhancement. It has the Dave Yousem meniscus sign,

3:24

that is the widening of the CSF

3:26

above and below the lesion,

3:28

identifying it as an intradural extramedullary lesion.

3:32

Here we have the typical feature of a

3:35

meningioma and that is a dural tail.

3:38

So you see, although we have the central mass here,

3:41

we have these little trailing areas of contrast

3:44

enhancement which identify this as most likely being

3:47

a meningioma rising from the dura as opposed

3:51

to a schwannoma. On the axial scans,

3:54

we again see a little bit of a trailing area of contrast

3:57

enhancement of the meningioma in the right

4:01

intradural extramedullary space.