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Pituitary Macroadenoma

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Dr. Shupack, this is a 52-year-old woman.

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I'm presenting you with a coronal T1,

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non-contrast on the far left,

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a coronal contrast-enhanced image, non-dynamic.

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So this one's pretty early,

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about one and a half to 2 minutes out,

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but not 20 seconds out.

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And then I've also given you an equilibrium phase

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or dynamic, sorry, non-dynamic, earlier phase.

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Sagittal T1 with contrast.

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So contrast-enhanced sagittal, contrast-enhanced coronal,

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non-contrast coronal T1-weighted MRI.

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We've got an obvious abnormality in the left portion of

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the pituitary gland. What shall we name the baby?

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Okay, so this is the lesion in question.

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I assume we can agree on that.

0:50

So it's in the pituitary and there's mass effect.

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Okay, so the stalk, we talked about some stalk deviation.

0:57

It could be normal, but in this case,

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you got a mass and deviation.

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So these two are related.

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Okay, so this is actually a mass,

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it's just not a signal abnormality.

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And the stalk's kind of bowed, too.

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If you go back to the stalk,

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it's got this kind of funny curve shape to it.

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And while that's obvious because there's a mass,

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if there wasn't a mass,

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you could have a curved shape or

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even a displacement or a slope,

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and that would be okay if everything else was all right.

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But in this case, it's not okay.

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Right. So we got a mass with mass effect.

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And also when we're talking about the sellar, remember,

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one of the things we're going to emphasize is

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what's around it in terms of structures,

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because that's going to have a lot to

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do with what ends up being done.

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And so here's your optic apparatus right here,

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and it's pretty close,

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although I don't think that there is mass effect on the

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optic apparatus. So we got an intrasellar lesion.

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Now, if we measure this,

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I think we can measure it at about 9 mm.

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Okay,

1:55

so a nine-millimeter mass hypointense on post-contrast.

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And you said earlier that an adenoma may do that.

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That is, it'll be cold.

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Sure. But if you wait too long,

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it can be iso intense and it can even be hot.

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Right. So you don't want to wait too long.

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You don't want to wait six, seven,

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eight or 9 minutes or you'll miss the lesion or confuse

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it with something else. But I wanted to ask you,

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it's 9 cutoff for a macroadenoma is 10 mm.

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What do we name this baby?

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Yeah, a big micro, I guess.

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A big micro. Big micro.

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Or a small macro. Or a small macro,

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but it's right on that border.

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But that's what you're looking for.

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That 1 cm, which is sort of an arbitrary thing,

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but nevertheless,

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that's sort of what you're looking for.

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So that 1 cm measurement.

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So anything smaller, theoretically at least, is a micro,

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bigger macro. This one's kind of right on the border.

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So you can kind of take whichever direction you want.

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Now, another thing is,

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what's going to happen, happen now.

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Okay, so we've identified this lesion.

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I think our differential is definitely

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going to be an adenoma.

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Okay, micro, macro,

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whatever direction we decide to take.

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So what's going to happen?

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Well, the goal of surgery is it going to

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be treated surgically? Well,

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there's not a goal in decompression because there's

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no pressure on the optic apparatus.

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So the other goal of surgery is endocrine.

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So if there is Cushing's let's say acromegaly,

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those are two life-threatening conditions that

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you would operate for endocrine reasons.

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Prolactin elevations of prolactin

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can be treated medically.

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So there's a pretty good chance that this

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is going to be not operated, followed,

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depending on the endocrine status.

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But from what we can see here, a substantial,

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but maybe not operative lesion.

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Let me ask you a clinical question.

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It's touching the optic apparatus,

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but not really compressing it.

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What if the patient still had a visual field cut?

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Right. This is something that you would follow,

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visual fields,

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meaning I had a bunch of patients with something like

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this. So we get visual fields as a baseline,

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and then a lot of times we'll just do it once or twice a

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year. And then if you see the fields are deteriorating,

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you reimage at that point,

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because then you would have an indication if

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there was a reproducible visual field cut,

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particularly a progressive one,

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and you can see that there's an extrinsic

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compression causing that,

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then you're kind of maybe getting

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into the surgical realm. Sure.

4:19

And unlike Rathke's cyst that we showed you earlier,

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where we didn't show you the coronal,

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but you had a kind of a big cystic lesion going up this

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way, and everything was draped over the top of it.

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So you had a cold area in the middle,

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and you had that so-called bear claw sign

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here in the sagittal projection,

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you've got circumferential tissue

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all the way around the lesion.

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It's not just the pars distalis and the stalk going up,

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making the bear claw.

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It's circumferential signal all the way,

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almost 360 degrees around the lesion,

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telling you it's intrasellar. It's in the pars distalis.

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And these are common lesions.

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They're 10% of all primary intracranial tumors.

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And in fact,

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these lesions are seen in about 15% of every autopsy.

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Now,

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we know microadenomas are inordinately more common

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than macroadenomas. In past studies,

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microadenomas are 400 times more

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common than macroadenomas,

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which tells you they're almost in everybody.

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I mean, not really, but they're super common.

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And when you do imaging,

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macroadenomas are two times more common

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than microadenomas. So, again,

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that tells you that these are very frequent

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as very small structures.

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And that's why a lot of times you may have a true

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prolactin elevation. And the MRI may be normal.

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It may just simply be a microscopic microadenoma.

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Right. Now, another thing about it, though,

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is that you talk about micro and macro and you think,

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well, okay, all the macros have to start off as micros,

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and they're going to get there, but not necessarily.

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There are really two different ways of behavior.

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A lot of the micros stay micros and then the macros

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really grow. Get to that size rapidly.

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So it's kind of a different entity.

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So you can have a micro that just sits there for years

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on end and follow them, but when it's a macro,

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it's a little bit different.

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This one may be more likely to grow

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than a tiny little one.

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I think that's both a scientific description of

6:13

it and that's been both of our experience.

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The micros behave very tight,

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they don't grow very quickly.

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And the macros,

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it's a free for all, so to speak,

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in terms of the secretory behavior of the lesion.

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You really can't tell that from imaging.

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But I will say that the signal intensity of a

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macroadenoma helps you understand a

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little bit about its histology.

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Most of the macroadenomas are iso intense with

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gray matter. But if they're bright on T2,

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they don't have to be really cystic,

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just brighter than gray matter.

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That implies that they're softer.

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And sometimes the softer ones can be a

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little bit more difficult to remove.

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And especially if you treat them with medical therapy,

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then they can get very gooey and hard to extract.

6:59

Is that a fair statement?

7:00

Yeah, I think that's correct.

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Now the other thing that you would

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want to look at a little bit,

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let's say you decided you did need to do surgery

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for some reason. Can you resect it?

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And I think we talked earlier about the cavernous sinus.

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And you can see that this one looks pretty clean

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over here. Maybe it's sticking in a little bit,

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but it's short of that mid carotid line.

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So this would be kind of that in that category one,

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grade one.

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So if you were going to resect it, that's a possibility.

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You're not going to necessarily have frank

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cavernous sinus invasion at this point.

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So let's explain that to him.

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It's in another vignette,

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but we should explain it real quickly.

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So the medial line along the medial

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border of the carotid right here.

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Then you bisect the carotids right here and

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then a line along the lateral border.

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So if this tissue extends beyond that lateral border,

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then it completely is unresectable.

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And how do you stage these?

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So over here,

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if you're short of this line medial to this line,

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that's a zero. Crossing these one, two and then three.

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Okay. And when you get to grade three,

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that is crossing that lateral line,

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crossing this last line, last line,

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those are the ones that you're going to have

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a hard time getting out surgically.

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And that may not be a reasonable goal

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of surgery up to grade two.

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You may have a decent chance of trying

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to get that out surgically.

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This is on correlation with endoscopy and pathology

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and it was published recently in

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the Journal of Neurosurgery.

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So just to be really clear for our viewing audience,

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a grade three would be here, my red dot.

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A grade two would be here.

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And there might even be a little component of grade two.

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In the upper compartment, there,

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a grade one would be here,

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and a grade zero would be here.

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And as you've mentioned many times,

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circumferential 67% or more surrounding the

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carotid artery. Carotid is also an.

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But another statistical way of saying

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that you're not getting it out.

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Your curate is not getting there.

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If it's less than 25% of the carotid circumference,

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you probably have a good chance of getting it out.

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Because, you see,

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there's an arachnoidal plane that may be preserved at

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that point that you can kind of get medial to get

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your curate and kind of scoop that stuff out.

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When you're getting that far beyond it, probably not.

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And then a couple of other easy points besides the near

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circumferential involvement around the carotid.

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But if you start to color in and opacify

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with intermediate signal intensity,

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the cavernous sinus you lose the cranial nerves,

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you lose the clarity of the carotid and

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then you have a nice dark interface,

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a black interface at the dural edge right here.

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Instead of just a line with signal on either side of it.

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That's an obvious sign of involvement

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of the cavernous sinus.

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A clinical sign would be if your prolactin level is

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1000 or 1500 or 2000 nanograms per ml, then you're

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probably just spilling cavernous sinus invasion

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right into the cavernous sinus.

10:09

Now,

10:09

just another little thing.

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The Framino Valley is a very important thing to

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assess when you're looking at the cella, okay?

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Because there are other lesions in the sella, tumors,

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things like that that can go right along there.

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And that's a very important thing to notice.

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And this one happens to show that yeah,

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I think I might have even accidentally earlier

10:28

drawn right over the foramen ovale.

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I think it's right here.

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Right? So there is the sella.

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If you got stuff in there,

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you got kind of a problem because it's out of the barn.

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Then nice and clean. And then just for giggles,

10:41

we have Meckel's cave here on the left.

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So with that,

10:44

we'll conclude our discussion of this pituitary

10:47

macroadenoma which is resectable if you needed to if

10:51

it was hormonally secreting in any adverse way.

10:53

It's not doing a lot of damage to the optic

10:55

apparatus yet. Let's move on, shall we?

10:58

Sure.

Report

Description

Faculty

Stephen J Pomeranz, MD

Chief Medical Officer, ProScan Imaging. Founder, MRI Online

ProScan Imaging

Tags

Sella

Neuroradiology

Neoplastic

MRI

Head and Neck

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