 All right, so again, since I have a captive audience, you can just see my travel slides. So these are the Grand Tetons. You've not been up to the Tetons in the Yellowstone, but it's only like 4 1⁄2 hours from there. It's beautiful, so get up there if you can. It's very, very nice. So they're not in the winter. It's very cold. Oh, let's see, am I not? That's awesome. The fun thing is that the Snake River runs right underneath the Tetons and then goes through a canyon in Idaho where the rapids are. So there's no rapids on this stretch of the Tetons, but if you want to see the mountains, it's a really nice way to go. So as you come along, as you can see, it's very placid, and so you just sit in the boat and take lots of pictures, which is nice. But the thing I like about it is, each corner you come around the river, there's just a new view of the mountains. They're just right up there, just sticking up out of the river, so it's quite spectacular. Some places people are actually out fishing, you see some moose, you see deer and elk, and you'll see all kinds of wild life along here. Here's our boat with our Intrepid Guy on it. As you can see, this isn't exactly whitewater rafting. I mean, people are just sitting there. You could have a TV in there if you wanted some. But it is pretty as you go through there. There's your Intrepid Raptor there. I mean, that doesn't even give you a cabin. It doesn't even give you the illusion that you're on the rapid sea. Basically just sit there and just passively goes down. But you just can't miss having a beautiful scenery like that right behind you as you come around every corner. Okay, we're gonna talk about the orbit today. Chris, tell us kind of how we divide the orbit into the main areas. What are the parts of the orbit? So we've got this cadaver I've seen and kind of an MRI view. Yeah, so intraconal, extraconal. Intraconal and how do we define the difference between intraconal and extraconal? The muscles. So what's inside the rectus muscles on the south side? Exactly. So you see the rectus muscles as they insert, they come back to the apex and they form a cone and there's an intramuscular septum around the rectus muscles. And so that really does tend to make a distinguishing, not a barrier, which is the distinguishing area between the intraconal and the extraconal. So there's definitely an intramuscular septum that divides it off. What's the most important things that run through the intraconal space? Optic nerve. Exactly, so the optic nerve, but also a lot of the blood vessels. The blood vessels and the nerves running out. What goes into the extraconal space? There's a lot of fat. Yeah, so not a lot of anything, some fat, some small blood vessels. Not a whole lot of anything. What's the third potential space in the orbit? Third potential space. Depending on what textbook you use, they'll often talk about a third potential space and that's the subperiosteal space. And so periosteum is what lines the bones of the orbit. So when you get an abscess, especially something arising from the sinuses, you can see the sinuses are right. They're medial to the orbit, they're inferior, they're superior. The location on that sinuses is temporally here. And so you do have a potential space in the subperiosteal space. So people will often call that a potential space. All right, so now we're looking at the orbit in a more of a sagittal type view. So here's the bone, glow, lid, you can see muscle, and then in the intraconal space, here's the optic nerve, a lot of vessels. And then the muscles here in the extraconal space, not a whole lot of exciting going on there. And you can see it again and again. In a scan, just shows you the relationship of sinuses adjacent to the orbit. So a lot of diseases that affect the sinuses can spill over into the orbit, including infectious, including inflammatory, and including neoplastic. And so you always want to keep that in mind when you're talking about the orbit. So not only can things that live in the orbit cause primary problems, but the tissue around it, especially the sinuses, can cause problems. All right, Beckham, what are we looking at here? Oh, I don't want it. Something that's gonna be really stimulating in me if you get this wrong. It is the lack of a gland. It's a good thing because I would have cried here if you got that wrong. And so when you look at these, it's glandular. And you see it's got this pattern we call assenur. And assenur means you make an acid here if you get this wrong. So it's assenur. So you can see it's got these round cells with the nuclei around the edge. And then you've got these little kind of redish-peaned granules in the middle. And then they dump into this little tiny assenine that eventually all those gather up and then it dumps into ducts. So this is a classic equirin gland. So these are sweat glands and these are also pachymal glands. So this is what the pachymal gland looks like. So we're gonna talk a little bit about potential things that can affect the lack of a gland. So Tara, what are we seeing here? You know, orbit is one of the hardest things because unlike the rest of the eye, this is the one place you can't see what's going on. So you have to try to infer. So when you see pictures like this, you try to look and you say, what's different about those two eyes? Is there a symmetry? Is there something different? If you look over here, there's a very subtle fullness here. And you see that eye looks like it's pushed down just a little bit more compared to this eye. So very subtle. And the problem is, is if you're gonna look at an orbit, you need to look at it with scans because you can't really see it. So what do we see in here on this CT scan? So people call that a coin shaped, coin shaped mass. What would you be concerned about there? All right, does decriadonitis give you a nice discreet cone or coin shaped lesion? Yeah, that's the key thing. So decriadonitis or lymphoid infiltrates give you more diffuse. And when we do an orbit conference, when Chris shows you those scans, he likes to talk about legs like putty and it goes around things. Now this is a coin agent. It's almost like there's a distinct, you know, quality around it. What would that be concerning for? Neoplasia. Okay, so you'd be concerned about a possible neoplasia. So when we look at this, this is a, this is that particular patient. Well, it's not, but let's say it is. What do we see in here? And if you look at them, they're kind of in a pattern. So you've got a proliferation of these little cells here. They almost look like they're glandular. And then in between them, in between these kind of little glandular looking cells, you've got this kind of this connective tissue and spindly shaped looking cells. What kind of tumor looks like this? And malt by definition is lymphoid. I'm not seeing a lot of lymphoid on you. It's a mixture of two cell types, proliferating. This is called a benign mixed tumor. Or, you know, some people will call it pleomorphic adenoma, but it's a benign mixed tumor. So in the olden days, when I was a resident, we used to have what was called the 50-50 rule. And that meant 50% of all lesions of the lacrimal gland were, you know, epithelioid derived tumors. And 50% of those were benign mixed. Well, when people really looked at it, especially the shields and the wills, they looked at all of the lacrimal gland tumors that they looked at. And they turned out that 80% of them were lymphoid. Either lymphoma or lymphoid hyperplasia. So the vast majority of these lesions are lymphoid. Decoradonitis, lymphoma, typical lymphoid hyperplasia. So the 50-50 rule's half wrong. But the second half is still correct. If you have epithelio derived tumors from the lacrimal gland, about half of them were these benign mixes, pleomorphic adenomas. And it's called benign mixed because they are characterized by this proliferation of both the glandular elements and then kind of the support cells around them. And benign, because this usually doesn't metastasize. And when you look at these, these often have this clean shake to them. And when you look at them grossly, when you try to remove them, although they don't have a capsule around them, they tend to slowly grow out and push the tissue adjacent to them so they get what's called a pseudo capsule. And when you remove these, instead of just doing a little biopsy, you wanna try to do an excisional removal completely because these will often shell out completely. And if you can remove these totally, then you've cured it. They don't come back. The problem we run into is when people will do a small biopsy, we're just able to partially remove them and there's still tissue left there. And when you leave them behind, they can go bad. And so you wanna try to get it all out when you can. Here's a close-up. You see you've got these glandular-looking elements and then in between these connective-type elements. Now, sometimes when you don't get them all out, they can go bad. And so even though it's uncommon, you can not only get a benign-mix tumor like the biopsy, but you can get a malignant-mix tumor. And it's pretty rare for these to arise just de novo, but usually it's in the setting where they try to remove a cleomorgo-gabinoma and these guys come back like this. And so you can get a malignant-mix tumor that's a lot less common. And I know it's subtle here, but when you look at these, you've lost a lot of that glandular element to them. There's a cleoli in here, there's pleomorphism in here. And so you can go on in formals called a malignant-mix tumor. And there you see a close-up of that. You see the cleoli and you see multiple cleoli here and you just see these cellular elements are a little bit more aggressive. Okay, other, Chris? So external photograph, the left end looks like a person had a chronic and also just breaks downward. Really it is very full from the lateral upper to the superior lateral area. All right, so you'd be concerned about the lateral gland and then your differential diagnosis, when you see more swollen doughy like this, it still could be a tumor, but again, it could be inflammatory, it could be depraved niacinitis. Any lymphoma on the list? Lymphoma on the list. Now, in this particular one though, let's say this is the scan. You see it's still almost coin-like, although there's still a little bit of some edges around it and so it's not quite that lymphoid look that you see although it's hard to see them right here. And this is what it looks like. What kind of connective tissue is this right here? It's like, it's pretty accelerative, so I want to say... Let's say a very hard connective tissue. A bone. A bone, exactly so. This tumor is actually going into the bone. And if you look, it's got almost like a Swiss cheesy appearance to it. What is that? What is that? Brace-alarm store. Swiss cheese oma? I can ask you a word that's invading the bone. How about a normal lesion that's invading the bone? So this is called an adenoid cystic. So this is the bad tumor of the lacrimal gland. So adenoid cystic is a bad tumor and the reason that this is really weird is usually the pathology of the tumors will tell you how aggressive they are. You look at like a sebaceous gland, carcinoma, it looks really aggressive. You look at a basal cell, it looks really benign. These look disarmingly benign. You look at it and they go, well, it doesn't look bad. And yet these could be really aggressive. And so on close-up, I apologize, it's not a good focus, but these cells do not look aggressive. They just do not look malignant. And the problem with these adenoid cystic carcinomas is they can metastasize. People die from these. And there's a particular subtype of adenoid cystic and you can get a Swiss cheesy one, you can get ones that have spaces all over them, but when you start to get these, they call this the basal-loid variety. And you can see it's almost like, kind of like really cellular, like a basal cell would be. So they call this basal-loid. These are particularly bad actors. So the adenoid cystics that go bad, this is the worst of them. And this is the basal-loid variety. These can be very nasty. They said, these can metastasize, people can die from these. Ashley, what do we see in here? So it's a real photograph of, it used to be a full-synth insulin, the right orbit almost apparent to losing. And again, you can see it's kind of superior, but more temporal than nice. So, again, that same differential, could this be diapgranitis? Could it be a funny lacrimal tumor? Could it be something infiltrative? And we kind of look at a scan, and this is a scan now that's more coronal. What does this scan show you? So there's really not a fight in borders of the matter. So what would you be concerned about here? Lymphoma. Yeah, something lymphoid, or lymphoma, or diapgranitis, or puttapiplasia. And so this is what Chris calls the silly-pity look. You've got that, instead of a distinct brown lesion, it's almost like it just kind of goes around structures and spreads around it, and not like it's fluid leaking there, but like silly-pity that you put around structures. And so this would be very suspicious for lymphoid type lesion, and indeed, so this is what lymphoma, lymphoid hyperplasia looks like. How do we tell the difference? Exactly, so flow cytometry, you'd have to do immunoproxidase staining, and so we go ahead and we do some staining, and let's say this is a, you know, kappa, a base stain, and they're all positive. Yeah, so B-cell lymphoma, and that's by far the most common lymphoma that we see in the orbit. It's a B-cell lymphoma, and it's now, they call it a mantle zone lymphoma, that's the new terminology we use. But basically, it's not that easy, though. I mean, there's lymphoma here, and there's, you know, dachryoadnitis, or just orbital, you know, inflammatory disease here, but in between, it's not that they're so distinct. It's in between, you can get some of your typical lymphoid hyperplasias, and sometimes you really do have to go and do the specialized stains to tell you for sure. So you can get lymphomas, and look what hyperplasia, both of the lacrimal gland, and of the orbit in general, and so it can arise just from either area. Eileen, what do we see in here? Okay, and what are coroidal folds usually signifying? Okay, but what's the most common cause for coroidal folds? Yeah, so hyperopia with the flat posterior eye is actually the most common, but if you're looking for lesions, this would be usually the sign of an intraconal type lesion. So you wanna look for, you know, livencies of the optic nerve, but this is what the scan shows here. Let's say this person is 25. Vague symptoms of fullness and pain are on the eye. Well, like cavernous dementia. Exactly, so you look at that lesion right there. It's not on the nerve, we're coming from the nerve. It's in the intraconal area of the orbit. And is this confirmed now? Yeah. All right, so this is the growth specimen, and you can see it's got a pseudocapsular, and then it's got these large, i.e., cavernous spaces, and so this is a cavernous hemangioma, and these behave a lot like the benign mixtures that I provide them, that you can shell these guys out. You know, when you get in there, once you get to the intraconal space, you can often just shell them out. They look like a little grape, and you just pop them out, and they'll come out whole. They won't bleed. Two inches nice, and they don't have a whole lot of vascular supply. So here it is, a low power microscopy, and then a higher power microscopy. So Eileen, what is this compared to this? A serum, so like the red blood cells have kind of settled out from the bottom. So what does that tell you? It's low flow. Exactly, so there's not a high flow through it. There's low flow. In fact, the red blood cells have settled down, so this is your little hematocritic here. So this guy's a trained athlete at high altitude. He's got a hematocritic of like 60% here. And so you see that the red blood cells settle out, and the serum sits above, and that's indicative of a low flow. And so you see they have these thin septate in between, and then these large vascular spaces here. And so this is a cavernous hematoma. Usually occurs in 20s, 30s, younger people, you know, lateral, you know, got a, you know, quasi capsule around it. It's got some condense connected to your abdomen. What do we see in here, Niko? So this is a external photograph. There's a here, so they're all shown in the right eye. Hard to say, maybe it's more problematic compared to the left eye. Again, I hate these pictures, because they show you these the orbit guys do all the time. They say, oh, you can diagnose people by looking at them. I can't. I mean, first thing I look at is I say, what's abnormal and what's not? But if you look closely, like there's some small show here, you always get an idea that that's just fuller on that side. There's something behind that pushing it forward. But it's not, you know, going down now. It's probably something behind it, not necessarily something above or a temple to it. Man, this is what we see on the pathology. What do we see in here? Very dense to me. Okay, dense cells. What is this? That, you know, when you see something like that, people call this a staghorn legion. So they look like deer antlers. You know, antlers on an antler or something. So, you know, when you're out there with your high-powered rifle that can shoot 400 yards, killing Bambi's mom, you know? You know, you may see some horns on there. So this is called a staghorn legion. And so what causes staghorn legions of the orbit? Look real close now. This isn't just extravasated red blood cells. If you look really close, look right here and here. There's little tiny vascular channels everywhere, all around this specimen in addition to these big staghorn spaces. Here's a close-up. One of these irregular staghorn spaces is a lot of cells proliferating in between. If you look at these arbolithetics, those are actually plump capillary endothelial cells. Lots of them, all kinds of little cells and then cells in between them growing. Yeah, capillary hemangiomas. Yeah, but there's too much proliferation here. Capillary hemangiomas usually don't have this much cellulary to them. What legion of the orbit has staghorn? The endothelium. Anybody? The mangioperecytonal. So I know you guys are sick of path and we're digging down to the second or the last lecture, but this stuff's in the book. Read it. Read it the night before. Read it the morning of, whatever. I mean, this stuff's all in there, so. Does the Lymphagyoma also have staghorn? Lymphagyoma has staghorn spaces, but not the cellular. Exactly, and we're gonna show you the difference in a second, but. So the staghorn is our spaces. Staghorn are our vascular spaces, yeah. They could be either lymphatic or blood vessels. In this case, these are vascular spaces, but if you look, they're everywhere. There's one there, there's one there, there, there, there. It's almost like you have these little capillary spaces everywhere. And then spaces here, and then the cells in between are proliferating. And so it's hemangioperecytonal. Proliferation is not only the blood cells, but also the pericytes. And here you can see another close up little staghorn space here, but if you look in between, little vascular spaces all over the place. Now, sometimes these can be more aggressive looking. And so when you look at these, they've got characteristic cellular findings. We will call these kind of benign, intermediate, and more malignant looking. But what's weird about these, I don't know why the orbit's so weird. Sometimes the benign-looking ones can behave aggressively. Sometimes the more malignant-looking ones can behave not quite so aggressively. So hard to predict. And so oftentimes it looks like, okay, this one's more borderline, or even maybe a little malignant. Look at those nucleolides, those pericytes are proliferating here. That doesn't necessarily mean it's gonna be bad, but these are not encapsulated like a caversum angiolum. These are tough to remove. And so when you remove these, sometimes it leaves parts behind. Over the years, they can undergo changes. And we've seen several patients here that like Rick Anderson started on 20 years ago and then Boopy's taking care of them. We've seen it evolve from a benign to an intermediate to more malignant-looking mangrove bear syndrome. So these could be difficult. As Boopy says, it's real bugbearance. This could be a bugbear to get rid of because they're not really encapsulated. And there you see one that's even more malignant-looking. Look at that. The nucleolide, the chromatin, the polymorphism. So these can go from benign to intermediate, borderline to more malignant. What kind of stain is this? Jason, why would I show this? It does or doesn't? Yeah, but it is. So why is there a lot more silvery black stuff in there than your run-of-the-mill trachrome? No, it's actually not a trachrome. That's a reticulation. It kind of looks like a trachrome. That's what I wanted to show you. Why would we stain with a retic stain on these particular lesions? Well, even more than connective tissue. Remember, pericytes are the support cells for the vessels, and they really help to make the vessels stronger and not leak as much. And so what happens is when these pericytes all start to proliferate, you get this reticular network from them. It almost looks like a net. A reticulum looks like a net. So when you look at this, if you wanted to do a reticulum stain, you get this net-like background stain. And so it kind of looks like a trachrome, but it's really not a reticulum stain. It stains that reticular network that the pericytes make, stains of silvery black. And so this is one stain that we like to do in these particular tuners. It seems to have a GMS stain. GMS will do a similar thing. Yeah, because GMS is a silver stain in the stain, but it stains more for things like fungal walls rather than the connective tissue. You could use that here also. What's the stain specifically in any kind of tissue? It's actually the reticulum is the little part of the pericyte wall that tries to add to the vessel wall to make it stronger. So that's what it's been staining here. All of you do it just because it's a teaching institution and you want to show the residents some things. So. That's good. Yeah, yeah, yeah. But no, I can help you if you're questioning the diagnosis sometimes, sure. All right, Lee, what we see in here. The CT scan, which shows, looks like an extra-colonel mass along the needle aspect of the whole bit. Doesn't look well-servic-escribed. Kind of looks like it's just diffused and just kind of putty-like to some degree. And it's not homogenic in terms of intensity. Yeah, so it's kind of heterogenic. I mean, there's some areas that are dark and not staining. There's some areas that are lighter and staining and it looks like a mixture of all those. It's not a homogenous lesion, it's a heterogeneous lesion. You can see it's causing a lot of proptosis. I mean, look at that. And that's some significant proptosis. So what if I tell you this patient is 12? So then you start thinking of concerns for tumor versus... Okay, and there's one other lesion that can give you this heterogeneous mass and you can get explosive proptosis in these. It can be cystic and then solid in between them. Here's that lesion. The big staghorn space. I mean, huge staghorn space. The most incredible staghorn space ever, that any of you have ever seen. So yeah, so this is a lymph angioma. And when you look at lymph angiomas, they can have these big, almost like lymphatic channels but then in between there's connective tissue and as you can see some areas of inflammatory cells. And so these lesions can often get these little pyrus patches looking lymphocytic gatherings there. What's interesting with these kids is sometimes they'll get an upper respiratory infection and their proptosis will increase. And so it's not that they can get these lymphocytes proliferate in the setting of an infection and these kids get increased proptosis. The other thing that can cause a sudden increased proptosis in these kids is this. What's happened here? So there's leading to the stasis. Exactly, so you can see here, there's still the classic lymphoid areas here. There's all these tiny vessels, but now you've seen bleeding into these. And so you can get an increase in proptosis when you get bleeding in these larger cystic areas of the lymph angioma. And these kids can again get an explosive proptosis if you go in there to try to drain them because the blood's been sitting there for a while. The red blood cells break down and it looks chocolate. And it looks like chocolate syrup. So they even call these chocolate cysts because when the red blood cells break down they start to look more brown and red and start to get kind of gooey. And so these are called oftentimes chocolate cysts. Now the problem with these lymph angiomas is again they're not encapsulated. They tend to send fingers all over so you go in, you cut it out part of them and then the part that's still there grows like crazy and it just comes right back. And so these are really tough to take care of. So sometimes as they get a chocolate cyst and they get this explosive proptosis people talk about using a CT or ultrasound guided needle and you go into the cysts and try to drain them without opening them up to do surgery. Is they usually in a setting of trauma where they bleed or just- Not necessarily. It can be under the setting of an infection or some kids, they score nothing happen. You know, kids are always bouncing around and you know if there's a trauma or not but trauma can cause it but not necessarily. And here again as a close up you can see these smaller, smaller staghorn spaces and then you see these inflammatory cells next to them and so these are thought to be the ones that will expand and grow when you've got a respiratory infection so you can get increased proptosis when these kids have an infection. So what's the name of the distinction between these and the conventional pericytes? It's the cellularity. So when you look at these you do not have that massive proliferation of the pericytes. And so when you look back at the hemangioparecytoma, I'm gonna go to the lower part. Look how cellular that is. That's just incredibly cellular. Whereas you look at these, these have these spaces that are a little bit bigger but there's some connective tissue here that there's not that cellular proliferation that you have in a hemangioparecytoma. And so would you also say that staghorn could be bigger? Staghorn's are usually bigger than this and so the staghorn's are bigger in hemangiomas. All right, what do we see in here, Chris? So significant inferior in kind of, or displacement of the glow as well as proptosis and kind of fullness of that upper eyelid as well. So some sort of kind of retrovolvary mass. How is this patient young? Yeah, so say this is a six-year-old. And here's the scan. Yes, kind of a diffuse infiltrative tumor with domino erosion with something like that. It's, you get very concerned with like a rabidomyosarcoma. Exactly. So in a kid with explosive proptosis like this in this scan, you worry about a tumor in the most, you know, tumor that fits this pattern into a rabidomyosarcoma. Now, this is true story. This is when I was a fellow. Young child, they did a tiny biopsy of this kid. There was this lesion that was, you know, maybe, you know, less than a centimeter in size. He said, oh my God, rabidomyosarcoma, we got to treat the kid. And so they admitted him to primary and admitted her to primary. And the kid, they started giving chemo and then the kid's hair started falling out. So mom and dad were divorced, by the way. So mom checked the kid out of primary and took her to Mexico. And you guys probably don't remember leitro. Leitro was the miracle cancer cure. And you know that evil, you know, industrial medicine complex that keeps, you know, our kids from being cured in the US, you know, wouldn't let leitro come in. And so people would go to Mexico and they'd give leitro and coffee enemas and then magic stuff that would make them feel better. Of course they would feel better because they'd blast them in steroids. And so dad hired a private detective who traced the mom down to Mexico. Dad went to Mexico, re-kidnapped the kid, brought the kid back up here. And now this is the kid's scan. So this is like in a matter of a few weeks. And so it went from a lesion, you know, this big to the whole bar, but the kid ended up having an exeneration and it was just really a mess. But so these tumors can grow very rapidly and explosively when you do these. All right, now, unfortunately, this was one from a Grand Rounds and I love this. I'm gonna have to like white out the pictures here that say it. And so this doesn't actually say it on here. So what are the main classifications of rabid cancer called the different types of flea morphic butyroic and... All right, so what's the most common? Plea, what do you think? Plea morphic. Or embryo. Oh, embryo, yeah. Yeah, embryo, embryo, whatever you want to pronounce it. That's by far the most common. And so when you look at these, we just had one of these a week ago. So please, got my, you know, got our things reported and all that. And so when you look at these, they'll often have kind of a round head and then kind of a thin little body coming out of them. But characteristically, they look like kind of tadpoles. And so they'll have a big head here and some of them will have a little tail coming out of them. But if you can, if you look closely, you can hallucinate cross striations. Since it kind of looks like a tadpole and then on the tail here, you've got these little cross striations. And so this is the most common type which is called embryo or embryo. And this has a moderate severity to it. And so these are kind of moderately severe, they're called embryo. And then this is in a trichrome statement. So trichrome tends to bring out the cross striations. So you put a trichrome stain on here. Look at the little tiger stripes on here. Because these are muscle derived, not mature muscle, but muscle rest cells, they think. And so you can see a little cross striations on here. So this is classic for this embryo type, Graptomino sarcona. There you can see a nice one, even in an H and E stain. All right, so this is one just with some special stains. So vimentin is a stain that stains muscle cells. And so it's an immunoproxidized stain that stains the cytoplasm brown. And if you look right here, you can see these cells all stain brown with the vimentin stain. So you know that this is a muscle derived tumor. All right, Becken, there's a particular subtype that's less common, these randos that's more aggressive and we worry about it more. Alveolar, why do we call this alveolar? Exactly, so this kind of looks like the alveoli in the lungs. And so when you look, you see these little thin septae here and then these cells kind of fill up in between there and line up. And so it almost looks like alveoli. You know, when you get kids that have pneumonia, you may have all the inflammatory cells in there, except here, they're tumor cells. And so you look right here, you can see that the cells tend to fill these alveolar-like spaces. And this, again, doesn't look more malignant, but it is. And so this is at least common of the rabbinomyosar problems, but this is the most aggressive. So this is the one we really worry about. So the alveolar is the kind that we worry about. There is one called a botryoid and there's some that are even less common and they are just really, really almost like muscle. And so some people will speculate that maybe they're just more normal muscle growing in tumor. So the two you want to remember is embryo and alveolar. And again, this just shows you an immunoperoxidase stain, staining them to show that it's muscle derived. All right, what do we see in here, Chris? The young person, buffed eyes, have a lot of dosis. Looks like all the fold is in their hematoma. Okay, so what would you worry about here? Just differential. So a lot of things where I talked about, I think that would have to be that kind of neurofibroma based on the erythema and grapidoma is still on the left side of the screen. Okay, so the old saying, if you hear hoof beats, so we've just described a unicorn and a zebra now, but what are the horses here when you hear the hoof beats? Orbital cellulitis. Exactly, so cellulitis or an inflammatory condition. That's what you'd be, those would be by far more common here than, you know, I'm just gonna keep you in the back of your mind, or abdo, or interferonoma, but most common would be either infectious or inflammatory, either cellulitis or, you know, normal inflammatory disease. And so when you look at this particular one, this one actually turned out to be a orbital inflammatory region. So I just don't usually, you just don't usually get biopsies of cellulitis because people just treat them and they get better, but this is one where this is the orbital inflammatory. So, orbit like lacrimal glands, you know, you've got your, you know, orbital inflammatory, we used to call it pseudo tumor, but tumors are bad words, you can't say it's pseudo tumor. So now we call it what? Well, if it's in the lacrimal gland, you call it that great announcement. It's just in the orbit. What do we call it actually? Orval inflammatory. Yeah, just orbital inflammatory syndrome, orbital inflammatory disease, we used to call it pseudo tumor, again, that's a bad word. So, you know, over here you've got this orbital inflammation. Again, over here you've got lymphoma. In between you've got some atypical lymph or hyperplagias. And so when you look at the inflammatory type, you'll often have some gathering of lymphocytes here. You'll get blood vessels between them. You'll get mixtures of lymphocytes and plasma cells or sometimes you can get follicles. Whereas in the lymphomas you get not so many blood vessels, not so many follicles, sheets of lymphocytes. And how do we tell the inflammatory from lymphoma? And actually lymphomas can sometimes get better on steroids initially. What could a pathologist do? Yeah, exactly. So just like we talked about on the lacrimal gland, you can do immunoproxidized stains. Or if you get fresh tissue, you can do flow cytometry. That'll tell you if it's clonal or not. So clonal means lymphoma, non-clonal means lymphoid hyperplagia or just an inflammatory lesion. Here you can see we've got lymphocytes. We've got plasma cells. You've got some connective tissues, some blood vessels. And here after a while, you can even get what's called a, we used to call these fibrous pseudotunals. So you can get a fibrotic reaction from these as you try to calm the inflammation down. These organs can get sucked in from the fibrosis from these lesions. And this is more, this you can see there's more fibrous tissue in here. So you can get a significant fibrous pseudotum or fibrous oral inflammation if you can't calm these down rapidly. All right, what do we see in here? Ashley. Just to have some of your spiral show on the left side and then you can see there's a little bit of more fullness to the left. Of course, but if you look here, there might even be some fullness here because it's kind of a young, I mean, I love this, that kind of that 70s, you know, like porn star must act, you know, look to it. But if you look right here, it's pretty young guy to have, like, you know, grammatical aces. And so he's got pretty a lot of fullness, both here and here, you know, for a young guy. And we do the scabs, and what do we see? So it looks like there's, I think it looks like there's some kind of Yeah, and even obscure and even, you know, a crystal called kind of dirty, fat in the orbit. So whatever's going on, there is something going on in the muscles, but it's also just in the orbit itself. And so, Well, but thyroid usually doesn't spill over like that. So thyroid usually doesn't spill over. So this does have some inflammation in the muscles, some myocytes, but it's spilling into the orbital fat now. Exactly. Ortho-inflammatory disease versus lymphoma. Again, and if it's bilateral, you can still get a bilateral inflammatory disease, but you know, if it's bilateral, you start thinking more of lymphoma. So you can see right here, this is a diffused sheet of lymphocytes. So you've got these moderately sized lymphocytes, some clumped chromatin. You know, I like to say, when you look at the past vessels, it looks like someone took a handful of lymphocytes and just like smeared them right on the slide. So you just get this whole sheet of these lymphocytes on here. So this turned out to be lymphoma, bilateral in this young man. And then you do the special staining to stain for the chronal B. All right, now this, unfortunately, I lean. I didn't have a scan of this. This is the real color gross exenteration of this patient. So what kind of color are we seeing in here? Yeah, bluish, almost black. So kind of some bluish black nodular stuff all over in here, what could cause that? Yeah, and so what kind of melanocytic tumor would we do an exenteration for? Melanoma, yeah. So now, you know, when you look at the orbit, there can be different sources of tumor. You can get primary tumors of the orbit. You can get tumors from the sinuses spilling into the orbit, but you can also get metastases. And in fact, if you look, if you did a bunch of autopsies, I think probably the number one orbital tumor would be metastatic. But that's just if you did autopsies because once people die of their tumors, say you've got lung cancer, breast cancer, whatever, it's gonna metastasize to a lot of places. And so if you did an autopsy of people dying of cancer, you'd probably find that orbital metastases from elsewhere would be the most common cause. But you can get tumors that arise from the eyelids, that arise from the sinuses, move into the orbit. So this happens to be a patient who initially had a conge melanoma that then kept coming back and he couldn't treat it. And so it ended up being an orbital melanoma and they had to do an exeneration at this point in just housekeeping. And once it's gotten that far, it's gonna metastasize elsewhere. And so you just can't have this tumor growing in the orbit. So they did an exeneration there. And when we look at it, this turned out to be malignant melanoma. And I know you can't tell these are melanoma cells on here. I'm sorry, but it's these plump cells right here with just a little bit of pigmentation on them and they're going into the orbital fat. So you can get tumors arising from the lid going into the orbit. And that can be squamous cell carcinomas. It can be melanomas. It can even be sebaceous carcinomas. And here's a closeup of those ugly looking melanoma cells. Nico, what are we seeing here? So it's an external photograph of the other communities in motorbikes. So we're in it here's the Earth's show. Motorbikes, some litter attraction. So this is Becca when I asked her the last question? No. And this is like the entire identity. Yeah. So this looks like that. So when you have that surprise look, people give you that surprise look. That often is thyroid is in the differential. And so what's the most common cause of bilateral proptosis in an adult? Thyroiditis. What's the most common cause of unilateral proptosis in an adult? Thyroiditis. Thyroiditis. See, you guys can listen. So that's good. So you can see right here, not only do you have this scleral show severely and inferiorly, but you get this little injection of the blood vessels here, especially around the rectum. And you see that real commonly in thyroid eye disease also. And here you can see this is the scan. Here you see it's not spilling over into the orbit. It's just in the muscles. And what's the difference in the involvement of the muscles in thyroid versus myositis? In thyroid. Thyroid spares the tendon. So see how the tendon is spared? So you see that the belly of the muscle is fat but the tendon is spared. Whereas in myositis, you can go all the way up to where it inserts in the eye. Now would you be worried about this particular patient with this scan? Yes. Why? There's a lot of thickening in the muscles like in the back so we can start for an optic nerve progression. Exactly. So look at this fat muscle belly is going all the way back to where the optic nerve comes out at the apex of the orbits. When you see that congestion posteriorly like that, you really worry about it because you can get optic neuropathy section. It's not obviously when the patient's really proctotic and the lids are really retracted, you can get exposure and all kinds of other problems. But these are the ones you really worry about when they're posterior. This is one I copied out of the book. This is an autopsy and look at that muscle belly. How big it is, but look at how the tendon is spared. So that shows it nicely in this autopsy eye. And when you look at these, they'll have this diffuse infiltrate, lymphocytes, some plasma cells, and then this kind of a demodus mixoid stuff. Now eventually, when this burns out, you can even get fibrosis of those muscles. So those muscles get fibrotic and shortened, people will get diplopia from the thyroid disease. All right, boy, this is a specimen, Jason, that you saw in the clinic, I mean in the path lab when you grossed this in. This was actually removed from the orbit. And we're trying to shine a light through them. What are we trying to show there? We're trying to show this thing we're very good at darkening. Actually, it doesn't show up well. And so we're actually showing how it kind of lights up when you do the light. So cystic. So cystic, so what's a big cystic lesion that you'd be concerned about in the orbit? Never a patient would be concerned about a dark white cyst. Okay, and indeed this was a five year old. So we open it up and this is it grossly. It's got all of this disgusting cheese inside. It's like caseating, so what would this be? Lusensis. Well, just what you said, I mean it's a dermoid. Now, how do we tell a dermoid pathologically? I mean, you see some epidermal features like epithelium, I'm just trying to find epithelium. And what else do you need beside the epidermal features? Then you need some dermal patterns as well. Exactly. So when you have a dermoid cyst of the orbit, that's different from the dermal corstomas of the limbus. These are cystic structures and you've got this epithelial lining just like skin, but you've also got hair and sebaceous glands and sweat glands. So you have dermal appendages along with this and when you look at it, and again, this is a fellow's picture here, I should be. See, I always, if they're blurry, you blame the fellow, shit. So I do the same thing when I show videos at meetings. If it's like a disaster, I say of course the resident's doing this case. And it looks great, I said, this is my case. But the fellow obviously took this. So you see this stratophyte squamous epithelium, the cyst is filled with care, but look down here. Here's a hair follicle, there's a sebaceous gland. So you've got epithelium, but also dermal appendages in these, and so people theorize that there may be surface ectoderms, sometimes in embryology that gets pinched off because it's often located along with the sutures between the bones are. So they think that maybe a piece of this gets pinched off and then it just grows throughout the kid's life and eventually causes problems. So when you remove these, you try to remove them all because if you spill keratin, in an orbit, keratin can cause a lot of inflammation. But sometimes these will spontaneously rupture and the keratin will spill out and they get lots and lots of inflammation. Okay, let's say bye to the Snake River. So next week is tumors, but also in terms of tumors, we're going to talk about leukocorea in kids. So know your leukocorea differential diagnosis. Questions? In that last case, how would you tell that if you're just looking at the growth assessment that it wasn't like fatty? Oh, yes, you can't tell. You can't tell, it does look fatty and it looks like it's just fatty lesion, but the difference is it's not solid when you put a light next to it, the light kind of transluminates through it so you know it's cystic. And it's rare for cystic structure to be totally filled with fat. So when you cut it, keratin is really disgusting. When you cut it, keratin is just, it's cheesy and it smells and it's really pretty, pretty effortless.