0:00

Dr. Laser,

0:01

a lot of your young colleagues often ask,

0:02

"Well, what's a meningioma? What really is it?"

0:05

Well, it's a tumor.

0:07

It arises from arachnoid capsules in the extra-axial space.

0:11

So, it's an extra-axial monoclonal tumor.

0:15

There's a meningioma gene, by the way,

0:17

so this is a good bar question where

0:19

you can win a free beer.

0:20

And that meningioma gene is found on chromosome 22.

0:25

It's no secret that in neurofibromatosis type 2 or NF2,

0:31

chromosome 22 also has a mutation.

0:34

So the meningioma, the isolated meningioma,

0:37

has an abnormality on chromosome 22 that is located

0:40

between myoglobin and the c-sis proto-oncogene.

0:43

And patients with NF2 have a different abnormality,

0:46

but also on chromosome 22.

0:49

Everybody knows,

0:51

or if you don't, you know it now,

0:52

that individuals with NF2 get multiple meningiomas.

0:56

And by the way,

0:57

speaking of multiple meningiomas,

0:59

there's also a phacomatosis called

1:01

multiple meningiomatosis,

1:03

which is frequently unilateral, but can be bilateral.

1:06

Meningioma, an extra-axial mass

1:09

arising from arachnoid cap cells,

1:12

demonstrated here in the olfactory groove on T1 C-,

1:16

T1 C+ and T2 spin echo MR imaging

1:20

in an extra-axial location.