Interactive Transcript
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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.
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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.
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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,
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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.
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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
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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.
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Is that a fair statement?
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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.
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Now,
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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
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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,
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we have Meckel's cave here on the left.
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So with that,
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we'll conclude our discussion of this pituitary
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macroadenoma which is resectable if you needed to if
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it was hormonally secreting in any adverse way.
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It's not doing a lot of damage to the optic
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apparatus yet. Let's move on, shall we?
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Sure.
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