0:00

Dr. Shupack, this is 61-year-old man,

0:03

has known prostate carcinoma,

0:05

which by the way is a lesion that can metastasize to

0:08

the brain and have a very kind of smooth, firm,

0:12

intermediate signal intensity when it's outside

0:15

the skull. But when it's in the skull,

0:17

it's going to be really, really dark on most sequences.

0:20

That's why it's the penultimate sclerotic metastasis.

0:24

Now, this person has a known cerebellar meningioma.

0:27

The symptoms that brought him in here are kind of vague.

0:30

We have a sagittal T1-weighted image right here that

0:34

shows a mass near to the cellar. There's the cellar,

0:37

there's the mass. We've got a T2 fast spin echo,

0:42

there's the mass and it kind of makes

0:43

this little snowman effect.

0:44

Is it connected to this structure underneath or not?

0:48

In other words,

0:49

is it another meningioma or is it an adenoma?

0:51

That's probably the main question to be answered.

0:54

And then we also have the coronal T1 C+ image to

0:59

go along and. So what's the diagnosis here?

1:03

We probably had fired our gun a little bit by

1:06

saying there's been a prior meningioma.

1:07

So that makes it more likely.

1:09

But why is it a meningioma? Right, well, first of all,

1:12

there is a dural tail, as you mentioned,

1:14

but it's in a classic location tuberculum sella. Okay.

1:17

So one of the that is really important,

1:20

where you think it is coming from when you talk

1:22

about a meningioma, where is it coming from?

1:23

And the reason for that is that one of the main tenets

1:27

of meningioma surgery is that when you're operating,

1:30

you can't just dig into the thing or you're going to

1:33

have a long day. You have to devascularize it first.

1:36

You get to the blood supply first.

1:38

So you're not coming from underneath this time? Well,

1:40

you are. You're going to go right here. Usually,

1:42

there's going to be some hyperostosis. Okay.

1:44

So basically what you try to do with these things

1:47

is kind of get under it, cut it off,

1:49

and then get into it once you've gotten the blood

1:51

supply. So meningiomas will come in classic locations.

1:55

Convexity falx, olfactory, grooved, tuberculum.

2:00

Classifying in that way is important because that tells

2:02

them how they're going to have to approach it to get to

2:05

the blood supply more than the mass itself. Yeah.

2:08

Let me ask you a real question,

2:09

just to interrupt you for a second.

2:11

If I showed you this case with all the other sequences,

2:14

would you then tell me,

2:15

I want a CT before I operate as a neurosurgeon.

2:18

A CT could be interesting for calcification.

2:22

Meaning if you think it's going to be like a rock

2:25

and you may have to prepare yourself for that,

2:27

a CT might be very useful.

2:29

Does the amount of sphenoid bone or

2:33

thickening does that affect what you do?

2:35

Or do you want to know that ahead of time?

2:37

I think you do want to know it.

2:38

And the reason is sometimes what you'll see is an

2:40

area of, like, a nodular thickening. You say,

2:43

that's where I'm going, because you'll drill that off.

2:46

You drill through the bottom of it and then you

2:49

vascularize it. And then when it's kind of floating,

2:51

no blood going into it.

2:52

You're going to have an easier time taking it out.

2:54

But this one is going to get treated because

2:57

it's got optic apparatus. Depression. Okay?

3:00

So next thing we say is, okay, diagnosis meningioma.

3:04

Fine.

3:05

Now we have to move on to what's the treatment going

3:08

to be. So you can go from either direction.

3:10

You tend to go from the nondominant side,

3:12

but this would usually be the right side,

3:14

the right side, at least in a right-handed individual.

3:17

But this one has a Sphenoid cyst. The question is, hey,

3:20

I got a little shorter.

3:21

So you're going to think about it. Now,

3:23

you still may end up going from the right,

3:24

but it's a good thing to say. Okay.

3:26

It's going to have to be treated. How?

3:28

Because then you're going to make comments that,

3:31

for example,

3:32

relationship to the anterior cerebral complex is an

3:35

important thing because they have

3:36

to take that into account.

3:37

They're going to have to peel that right off the top

3:39

of this. Meaning you're going to get in there,

3:41

there's going to be an arachnoidal plane,

3:42

you're going to want to lift that

3:44

up away from the thing.

3:45

So all these things that the surgeon

3:46

is going to be thinking about,

3:47

you want to be thinking about and put it in your report

3:50

so that you're part of the team devising this treatment.

3:55

Sure.

3:55

Now there's probably three compressive

3:58

structures that you're interested in.

4:00

Already pointed out probably the most important one,

4:02

which is the optic apparatus,

4:03

and that's a good reason to operate on it.

4:05

Another one would be what's happening with the carotids.

4:08

Now, sometimes the carotids will get splayed,

4:10

pushed apart, and that can happen with any mass.

4:12

It happens with arachnoid cysts.

4:14

But one thing meningiomas like to do is they like to

4:17

grow in a kind of a lipidic sort of surface-like

4:20

fashion, so they can wrap around the carotid,

4:22

but when they wrap around,

4:24

they can choke the carotid and narrow the carotid.

4:27

So you really got to look at the size of

4:29

the carotid arteries on either side.

4:31

And then the last compressive thing you want to check is

4:34

the pituitary gland, because you can get stalk effect,

4:37

you can get prolactins up to 100,

4:39

almost never above 150 nanograms per mL.

4:44

But if you get really severe compression,

4:46

then you can get pituitary insufficiency.

4:48

So pituitary gland compression, keyismatic compression,

4:52

compression and narrowing of the carotid arteries.

4:54

Those are three key things that you want to put on your

4:57

checklist. And then this lesion is. Pretty smooth,

5:01

gray lesion.

5:01

You can see it's slightly different in

5:03

signal from the pituitary gland.

5:05

It's slightly different in enhancement from the

5:07

pituitary gland. It has a plane of separation.

5:10

But there really aren't very many things that go

5:14

supercellar that are this gray and this smooth

5:17

on every sequence. And, you know,

5:19

they really boil down to adenoma macroadinoma.

5:22

We've already established it's not because we've seen

5:23

the plane of separation. Then you've got meningioma,

5:26

and then after that, it's very slim pickings.

5:29

I have seen germinoma do this.

5:31

I've seen a sarcoidoma do it.

5:33

But other than that and lymphoma other than that,

5:37

very few lesions are going to give you this smooth,

5:39

gray appearance. So it's almost definitive.

5:42

It's almost diagnostic empathic mnemonic for a

5:46

meningioma. Shall we move on? Yes, let's do it.