0:00

This is a 64-year-old woman with a known pituitary adenoma.

0:04

And it's a macroadenoma.

0:06

And it has all the typical characteristics of it.

0:09

It enhances pretty homogeneously, not as intensely as, say,

0:13

a meningioma, not as early as a meningioma.

0:16

And if I put up the T1 non-contrast, which I haven't,

0:19

it would match the signal of gray matter.

0:21

It matches the signal of gray matter on this coronal T2-weighted image.

0:25

And typically, these lesions,

0:29

when they have suprasellar extension,

0:31

they may get a little bit pinched off.

0:32

So they may make what's called the snowman effect or a

0:35

figure-of-eight effect because the diaphragma sellae

0:38

pinches in on them.

0:40

And then when we're looking at these macroadenomas,

0:42

we want to see if there's presellar extension,

0:44

retrocellar extension, suprasellar extension,

0:48

which there is, and cavernous sinus extension,

0:50

which at first glance you would say there isn't.

0:53

I'd like you to take over from there.

0:55

Sure.

0:57

We talked about what's the clinician's question.

1:00

Okay, one of the questions here is,

1:03

is this a surgical candidate and what are my chances?

1:06

Okay, first of all, is it a surgical candidate?

1:09

Well, you have mass effect on the optic apparatus.

1:12

So that's kind of a classic indication for decompression.

1:15

It is one goal of transsphenoidal surgery.

1:17

She's a transsphenoidal candidate. Remember,

1:20

the sella is aerated. The cell is big,

1:22

big enough to work through.

1:24

Okay?

1:24

So somebody's going to be given serious thought to operating

1:27

on it. Now, another question is going to be, well,

1:29

can I get this thing out?

1:31

Can I cure this surgically?

1:32

So that's what takes us to the cavernous sinus, okay?

1:35

Because if it's not in the cavernous sinus,

1:38

there's at least a theoretically decent chance

1:41

that you can get that lesion out.

1:43

You cannot get it out surgically of the cavernous sinus.

1:46

So we have to kind of make an assessment.

1:48

And the clinician wants us to make an assessment, is,

1:51

is it in the sinus or not?

1:53

Okay, so we're looking here.

1:55

And so what you have to do is really get a good handle

1:58

on the carotids. Okay? So here's the carotid borders.

2:02

And what I do often is make lines.

2:04

Medial border of the carotid.

2:06

I'll draw the lines for you.

2:07

I'm a good line drawer.

2:08

Right. So medial border of the carotid.

2:10

One right through the carotid center.

2:13

The center of the carotid.

2:14

Right. My line's a little fat, but that's okay.

2:17

And then the lateral border and along

2:18

the lateral border of the carotid.

2:20

And the reason I bring those lines up is because there are

2:23

classification systems based on which

2:26

of those lines are transgressed.

2:29

It

2:32

goes beyond okay, so if it's going beyond that lateral line,

2:39

it's not going to get resected.

2:42

If it goes beyond the medial line,

2:45

there's a chance of resecting it.

2:46

That would be a class two.

2:48

Okay. Grade two. So if it goes beyond this line, okay,

2:51

so if it's on this side of the line,

2:53

that's not in the cavernous sinus.

2:55

If it's in between these two, that's a grade one.

2:58

Grade two. And then when you get

3:00

out here, grade three.

3:01

And also there's a grade three A and B,

3:04

upper and inferior compartment. So an A would be over here,

3:08

and a B would be down here, down here.

3:11

And as it turns out,

3:12

when they correlated with endoscopic

3:15

data and surgical tissue,

3:18

once you get to a three B that is in this inferior

3:22

compartment, the chances of resecting start going down.

3:25

Meaning even if it looks like it's in here and it's a

3:28

three A, you do have a chance of curing that one.

3:30

When you get to a three B, that is,

3:33

it's kind of the basilar portion of the cavernous sinus

3:35

that did not correlate with resection as well.

3:38

So that's the kind of information that your surgeon is going

3:41

to be looking at, saying, is it in the cavernous?

3:43

Where is it in the cavernous?

3:45

By the time you're really encasing the carotid.

3:49

Okay,

3:49

if there's encasement of the carotid greater than 67%,

3:52

I believe that is considered to be not going to resect that.

3:57

Sure. Okay. If the carotid is less than 25% of its diameter,

4:01

in case there's a good chance of getting that out.

4:03

So there's a couple of statistics and

4:07

some classification systems you can use.

4:10

But that's one thing your surgeon wants to know is,

4:13

am I going in to get this out completely,

4:15

or is that not a reasonable goal of surgery?

4:18

Well,

4:19

let me just summarize in my simplistic radiologic brain

4:25

what you're saying in this extremely subtle case.

4:28

So we have three lines that we can make,

4:31

one line along the medial border of the carotid,

4:34

and we don't want this adenoma to go beyond that line.

4:36

If it goes beyond that line,

4:38

we're starting to grade the degree

4:41

of cavernous sinus involvement.

4:43

Then our second line is going to go right through the middle

4:45

of the carotid siphon, and if it's between here,

4:49

that would be one grade,

4:50

and then our third line would be along

4:52

the peripheral edge of the carotid siphon.

4:54

And if the macroadenoma goes to or beyond that line,

4:58

that's another real serious grade.

5:00

And then we break them down into A for upper and B for

5:03

lower. So this one, if you look very carefully,

5:07

you can see it's scooching right underneath the

5:09

inferior aspect of the carotid right there.

5:12

And if you have any doubt,

5:13

let's go over to the sagittal projection when we get out to

5:16

the carotid siphon. It's nice and clean around there,

5:19

and then we go to the other side.

5:20

Granted, it is a little bit of a noisy image,

5:23

but look at the same locus.

5:25

It's kind of fuzzy and ill-defined,

5:28

and that correlates exactly with this spot right here.

5:31

So we do have extension laterally.

5:34

It probably does go out at least to maybe the intermediate

5:38

line and probably to the third line.

5:40

And when you look very carefully

5:42

on the T2-weighted image,

5:43

and I'm going to make it a little

5:44

bit brighter for you to see,

5:46

you'll note that there is asymmetry right there

5:49

when compared with the opposite side.

5:51

So there's a little fullness under the carotid

5:53

on the right and it's not on the left.

5:55

So this is an extremely subtle example of cavernous sinus

5:59

involvement, probably on the order of A3B,

6:03

according to the classification criteria that you've given.

6:06

Correct?