 Laurent Jauré in Paris and this is the museum that was built around Monet's life-sized water lilies. Monet painted these massive water lilies that are the size of that hole back well over there and they basically built a museum around them. This is what it looks like. It's curved and you're just immersed in water lilies on both sides. It's got a white roof, white light. It's really pretty cool. These are life-size water lilies. If you like Monet, it's great. If you don't, just close your eyes and go to sleep. But you can see that there's various different paintings all along here and there are several different rooms shaped in circles. You can go and look at the various different paintings that are there. This just shows you have to go to a wide angle to get it all in. So it's actually pretty nice when you do that. Right outside of that, of course, is the gates leading to IMP's pyramid, leading to the Louvre. Or as they'd say here in Utah, the Louvre. So there's a Louvre where you get to see all the good patrons there. And there's the pyramid that IMP built later. So it's kind of interesting to see a modernistic glass pyramid in a 200-year-old glassy museum. But this is where you line up to get in. Actually, you go in underground now, right here. And you've got some really beautiful fountains there. So, orbit. Alright, so we talked about orbit a little bit last night. Now you can't really talk about orbit without realizing what makes up the orbit. One of the things that we always like to go over here is the bones of the orbit. And so, how many bones are there in the orbit? Reach out. Seven. Seven. Let's start. Name one. Frontal bone. Frontal bone. Alright, hang on. Axillary bone. Axillary bone. You're a student. I'm Cole. I'm the new intern. Oh, you're Cole. You're the intern. Oh, I thought you didn't start till next month. Alright, why you at the va? Yup. Alright. Well, welcome. Well, you get a reprieve for one lecture. But next week, read on tumors. Okay. Sphenoid. Sphenoid. Alright, that's three. Ethnoid. Ethnoid. Four. Lachromo. Five. Palatine. Palatine. Six. No, no, we'll get you good. I won't do it. Lachomatic, good. Alright, so, people often forget the little palatine bone. That's really one that people do forget about. But, the other thing that you've got to realize is what's around the orbit. And so, again, when you're looking at the orbit here, medially but also inferiorly and superiorly, there are sinuses around the orbit. So any diseases, any infections, any inflammations, any tumors that affect the sinuses can affect the orbit. And of course, we talked a lot last night at orbit conference about the orbital apex, a very busy layer where nerves and things go out of the eye, nerves and vessels go into the orbit. And so very, very busy area here. And then, of course, behind that, you've got a lot of busy anatomy back here. So the key thing when you want to think about the orbit, there's not a whole lot that goes on in the orbit, except for the fact that the orbit houses the globe, which is the most important thing that we think about with the eye. This just shows a little bit in a sagittal section. Now, Arianna, how do we subdivide the orbit? What are the main areas that we break the orbit into? And what's the third potential space? So periosteal. So if you look at the extracutor muscles, the muscles in the intramuscular septae make a cone. And so basically the base of the cone is at the apex of the orbit, and then it forms as the muscles go on to the posterior part of the globe. So this is intraconal. Extraconal is the area outside of the muscles in the intramuscular septum, which is not a whole lot going on in there, some fat and a few little vessels and nerves and things. And then the periosteum lines the bones of the orbit and there's a potential subperiosteal space where you can have, again, infectious processes coming from the orbits, hemorrhages, things like that are coming from the sinuses, I mean, and things like that that can form this potential subperiosteal space. And this shows that in an MRI scan, the most important thing in the intraconal space is obviously the optic nerve and the vessels and nerves that go through here and then the extraconal space and then the subperiosteum is a potential space. All right, what are we looking at right here, Ally? All right, so we've got these eccrine glands that are forming this little assener pattern. Why would I be showing you these in an orbital lecture? Lacrimal glands, good. So you're not, my mind would have been stimulated had you not done that. I would have been crying up here, but so the lacrimal glands, you remember there in eccrine gland, they've got this assener pattern where they form this circular pattern and they do their secretions into the central part of the lumen right here. You'll see that they'll often have this little kind of the acidifilx staining granules in them. Now, what else goes on here besides just the glandular part of the lacrimal glands? Brad, what other cells are in there? Well, not many fat cells in the lacrimal gland. What other cells are there beside the sacrum? Oh, we were talking about it inside the lacrimal gland. Mesenchymal cells. Mesenchymal cells, and what are those usually comprised of? Yeah, little myoepithelial cells. So little cells that kind of surround these asseni, these little spindly shaped cells. And I like to think of them in simplistic terms. So my simplistic way of thinking about them is these are little cells that squeeze the gland so that the secretions can get out. That's way too simplistic, but remember not only are the lacrimal glands made up of the epithelial cells that make the secretions, but also the myoepithelial cells that surround them. So those are both in the lacrimal glands. There's another type of cells that kind of live in the lacrimal glands. Sneha, what other cells live in there? I mean, those are just modified myoptheism cells. Anybody, people forget this all the time. Lymphocytes live in there. So wherever you have mucus membrane exposed to world, you'll often get some little gatherings of lymphocytes, almost like pyrus patches that you have in the gut. So not uncommon in the lacrimal gland. You have these little, almost pyrus patches, groupings of lymphocytes, and they are mostly more T lymphocytes than they are B lymphocytes. Right, we're looking at, you know, that's the hardest thing about orbit. Orbit is the one part of the eye we can't see. And so oftentimes when we're looking at the orbit, we almost have to infer something going on. And so before we jump in and order an MRI scan, we wanna look for subtle findings now. The one thing nice about it is orbits, there's two of them. And so we can often compare. Do we see anything very subtle that we can compare to? Boy, this is really subtle. And this is hard when you're looking at orbits, because if you look at it, look at that little light reflex, where that is in the pupil. And you look at the light reflex here, just a little bit higher. And it's very subtle, but you don't quite see the wrinkles as much here as you see here. And so you almost get an idea that there's a vague fullness there and that that eye may be pushed down a little bit. And we look at the scan here, the CT scan. What do we see in here? Exactly, and people would call this a coin lesion. By coin it means it's kind of rounded and it's pushing the eye in and down and it's got a little bit of a border around it. So what would you be concerned about here? All right, so you'd be concerned about either an inflammation and infection or lacrimal gland tumor per se. And we look at the path and this is what it looks like. What do we see in here? Exactly, so you see that this is almost like glandular. Some of them are more tubes than small glands, but it's glandular. But then there's all these kind of little spindly cells proliferating with this ground substance in between. What do you think this lesion would be? Exactly, pleomorphic adenoma. The other word they call this is sometimes they call it a benign mixed. So it's a pleomorphic adenoma. And this is the most common tumor derived from the lacrimal gland tissue itself. It's a pleomorphic adenoma where we call it a benign mix. And so it's a mixture of this proliferation of the little glandular epithelial cells themselves and then the little cells that surround it. So that's the name benign mix. Here's a close-up. You've got this proliferation of these glandular cells. Sometimes they'll form round, almost look like lacrimal glands. So sometimes there'll be these little elongated, almost tubes. So they form these little tubes of the lacrimal gland. That's a bad one. Let's see if we've got a better one. It's weird. It shows up really nice on mine and not so, not so well here. All right. Now I know it's hard, Ariana, but this is a person. They had a pleomorphic adenoma, a benign mixed tumor. They removed it. Patient came back, you know, six months later, swelling, lesion in that area, and they did this. Sheets of blue cells with some cystic species or some blood vessels. The recurrence is more concerning for blowing the process. So I'm looking, I could imagine that some of these cells are in many tubes. Oh yeah, I'm sorry that doesn't show up. If you guys came and looked up here, it shows up really nice up here. You can certainly see there's nucleoli, there's clump chromatin. It's still attempting to form glands, but look at that, look how active these cells are. So what does this tumor become now? And so what we call this, if the other one was a benign mix, we call this a malignant mixed. So much less common, but the key thing when you see an initial pleomorphic adenoma or benign mixed tumor, those often have a pseudo capsule around them. They grow slowly, they kind of push out and have a pseudo capsule. So if you can get the whole thing out, this is where you want to do a complete excisional biopsy, then you can cure it. But if you leave some inside there, you can't get it all out, then they can come back when they come back, they can be more aggressive. So it can go from a benign mix to a malignant mix. So that's what you worry about. So you want to make sure once you, you know, once you're convinced these are tumors, remove the whole thing. All right, Allie, what do we see in here? We see some hypoglomus. To get the idea, something's here, it's pushing that eye down. Again, what area is that in? Lachomobland. And we look at the scan here, and you can see that it is, it's still attempting to be round, but you kind of lose the tail here, you don't quite have as good of borders there. And this is the pathology. What do we see in here? The center, there's lots of like a collection of cysts, new tissue, and then there's also bone on this path. Yeah, this is actually even going into bone a little bit. There's a little bone there, and it's kind of invading in. What would your concern be here? Exactly. Now, adenoid cystic carcinoma is much more aggressive than the polymorphic adenoma. The adenoid cystic can actually invade bone. It can metastasize. This is one of those cells, one of those types of tumors where people use the term disarmingly benign, meaning you look at these, they look benign. There's not nucleolau over the place. There's not mitotic figures all over the place. You look at me and say, yeah, this is pretty benign looking, but it's not. So this is really, really, it's hiding. It's a wolf in sheep's clothing, if you will. So it looks disarmingly benign, but it's really not. And there are various different ways this tumor can present pathologically. All right, so Brad, what is this? Growth pattern is this. Now, that's really not what they call it. What do they call it? Basalloid pattern. That is one of the patterns. Is this a basalloid pattern? I thought so, I guess not. All right, so this looks kind of like Swiss cheese. And so this is what we call a criberform or Swiss cheese pattern to it. So you see it's got these little spaces in it and it's got the tumor cells around it. So this is called the criberform or Swiss cheese, these little spaces all through here. And so this is fortunately the most common form of the adenoid cystic carcinoma. There you see a close up, these little Swiss cheese spaces in between cells around them. And again, don't look really benign. All right, what pattern is this now? This is the basalloid. And so you see it almost looks like a basal cell carcinoma. It's really cellular. You kind of lose the glandular pattern to it and it becomes really cellular. Why is this important? Exactly, these are the nasty variant. And so when I said that you can get some really aggressive tumors that can actually invade into the bone, they can invade out of the orbit, they can metastasize distantly. It's usually the basalloid ones that are the ones who do it. If you see this basalloid pattern on this, you know, adenoid cystic carcinoma, these are the really bad actors. So these are the ones that you don't want because this is the basalloid pattern. These are the bad ones. So if you see that pattern beware, these are the really bad ones. All right, what are we seeing right here, Sean? So what would your differential here be? So we look at it. Now if you look at this, it's a little bit different. So this is what we call almost a pancake lesion. So instead of that specific coin or round-shaped lesion, this one, it's almost like silly putty. It goes around the globe and goes around the structures. And if you look, not only is there some over here, but maybe there's even a little bit some over there. You look at the pathology, what do we see in here? All right, so a big lymphoid proliferation and we do an immunoperoxidase stain and it stains like this. Do you think that they're lymphocytes? So don't forget, you can get lymphoma, the lacrimal gland also, but you can also get decryladinitis with lymphocytes in them, so you can get inflammatory lesions. And so back in the olden days, when I was a resident, they used to have what's called the 50-50 rule. And they said, okay, 50% of all lacrimal lesions are epithelial derived and 50% of those are benign mixed, pleomorphic adenomas. Well, it turned out that that's really not correct. When the Schiels and Wills looked at all of their lacrimal lesions that they biopsied, turns out almost 80% of them were lymphoid-derived somehow. Either lymphomas or decryladinitis or lymphoid hyperplasia. So really, in reality, about 80% of the lesions of the lacrimal gland are lymphoid-derived, not necessarily lymphoma, but lymphoid-derived and only 20% are epithelial derived. But of those 20%, half are still benign mixed. And then, of course, the rest are the others we talked about. So half of the 50-50 rule still takes hold. So remember, when you see a swelling in the lacrimal area, chances are it's gonna be more lymphoid than it is an epithelial derived tumor. What are we seeing right here, Mike? Caroidal folds. So what do you worry about when you see caroidal folds? All right, so those are the two things. We used to be taught, again, that this meant that there's an intraconal mass. So you'd worry there's an optic nerve tumor or another tumor that can occur in there. But when you really looked at them again, it turns out short eyes with a flat posterior sclera can give you caroidal folds too. And those turned out to be even more common than intraconal tumors. But let's say, for example, that you looked at this and you said, wow, this is a concern. Maybe there is an intraconal tumor here. So you worry about it and you do a scan and you see this lesion. What are we seeing here? What are we seeing here? Thus the name, cavernous hemangioma. So for some reason, these tend to occur intraconally. That's the place they usually occur. The symptoms are vague. People will complain of just some vague soreness, maybe some funny washing out of vision on occasion. And then you look at them and when you do the scan, they'll be well circumscribed. So again, these are ones that they grow really slowly and they tend to slowly push out. So they don't have a real capsule per se, but it's a pseudo capsule. So they push on the connective tissue, which kind of gets condensed. And so these really do have a pseudo capsule around them. So when you go to remove these, these really do just shell out. You just pop these out and they've got these large so-called cavernous spaces with the fiber septae in between. Catherine, this is a little higher power picture. What does this tell me about this lesion? Why am I showing you this picture? Yeah, a lot of red blood cells. The fact that there's red blood cells tells you there's low flow. What tells you there's low flow? If you look right here in each of these spaces, here's the red blood cells down here. Here's the serum up here. And so the red blood cells have settled down to the bottom. The serum has settled up to the top. So when you get separation like that, it tells you that they're stasis. And so it tells you that these are low flow. And so the nice thing about these when you take these out, they don't bleed like crazy. You know, when you have a capillary hemangioma, they're usually more in the lid than the orbit, but boy, those things, they bleed like crazy. But these have stasis in there because the red blood cells have settled down. So like this guy's hematocrit is 60. So they're a blood doper, you know? So they really got water. Man, that's too early in the morning. You guys just, just, just, just. That's humor or, or, or, or, all right? So. That's our story. We're looking at a guy here, Rachel. Dan, one of those things, what's the, you know, what's the side that's affected? These are so hard. That's what Boopie always does this to you guys. He says, you got to use your brains and not run to a scan. And so again, it's very subtle, but there are some changes here. The fold there, as opposed to the fold here. And look at the space between the lower lid and the limbis there and the lower lid and the limbis here. You kind of get the idea and look how it's fuller there that maybe there's something behind there pushing that right eye out. Very subtle, but again, it's a little bit more prominent here. And if you were to do a hotel, this eye would be more proctotic. But this time it's not down or in, it's out. So as if there's something behind it. And then we look at the scan and we see this. What the heck is this thing? It's fibrous materials. Exactly. You see these kind of long vascular channels, but you see a lot of smaller vascular channels here. And these are called staghorn, like a deer. So the deer horn sticking out. So staghorn spaces, lots of blood vessels. And then we look at a close up. Some of these have this funny irregular shape to them, but not only are these all, these plump endothelial cells proliferating, but look at all the cells in between that are proliferating. What do we call this lesion? Exactly. So this is not a hemangio, it's hemangio pericytoma. So it's a proliferation, not only of the endothelial cells, but also of the pericyte surrounding them. And so you can see in the preactive, look at the little nucleoli in there. So this is a hemangio pericytoma. What's this? And this is a close up here. You see these little staghorn spaces, which you can see there's a whole bunch of just little tiny vascular spaces all around them with proliferation of the pericytes in addition to the endothelial cells. Now what does special stain we can do that can help us tell for sure that's what this tumor is? Reticulum stain, I'm sorry. Close up showing you how they can be. Now the other thing that's interesting about these is they can be kind of benign, intermediate or more malignant looking. But just when you memorize that, you see, okay, we're gonna look at this, we're gonna see how it behaves. It's not necessarily correlated with how these behave. And so these are one of those ones that's really tricky. You can get some that don't look that bad on the path and they come back aggressively. Others look pretty aggressive on the path and they don't do much. And so it doesn't really correlate, but sometimes you can see where you remove these they come back, they come back a little bit more aggressive looking. And so we try to categorize them, but it may not mean anything. And so this is one that is more malignant looking. You can see how it's got these nucleoli in here, the cells are growing more, got clump chromatin all over. So it can go from a more benign to an intermediate to more malignant appearance with the Imangio perisatomas. And again, the stain that you said is reticulum stain. Why? Why does that stain? Well, it stains the reticular network around the little capillary channels, which is really what the perisites make. And so if you do a reticulum stain, you can see that it's got this little net, these little tiny nets all over the place here. And so this tells you that it's making this reticular network around the cells. And so it's really helpful to do a reticulum stain. What do we see in here? Allie, what you're calling a heterogeneous? Would you be concerned about when you see something it's heterogeneous. There's almost some fluid levels in here. It's really kind of mixture of what's going on there. All right, so let's give you, I'll give you a little bit of history. This patient is 10, 10 years old. Does that help any? All right, so when you see this heterogeneous, especially in a child, you want to start thinking more toward lymph angioma rather than immune angiomas. That's kind of a misnomer. It's not really just lymphoid channels perforating, but when you look at these, you'll see these large, almost like large lymphoid spaces. They have kind of this incomplete, spindly, flattened, endothelial lining around them. A lot of connective tissue. And then again, you get almost these little pires, patches of lymphocytes seen around these lesions. The reason that that's important is, these are interesting. Sometimes when these kids will get an upper respiratory infection, these lesions will grow, which is weird. So they'll get more proptosis. Chris, what's happened here? Another reason why you can get rapid increase of, ah, God, I did it. I called you Chris for a year, I'm sorry, Brad. I knew I was gonna, God, I knew I was gonna get, not get through the day without saying that once. All right, sorry, Brad. Sorry, Brad. You were just too nice to correct me when I called you Chris for like six months. Brad, what is that that we're showing you here that could also cause a rapid increase in proptosis? Well, so you could get bleeding into these spaces, which just looks like it has occurred here. Exactly, so sometimes these will have all these little vessels in between and one of them can bleed. And so you'll get blood into these channels and you can get a pretty rapid increase in proptosis. And so sometimes as the blood sits there for a long time, red blood cells degenerate, they turn almost brown. And so they call these chocolate cysts. And so if it's really bad proptosis, it's threatening division, people will often go in with either an ultrasound guide or a CT guide, put a needle into some of the big cysts and drain them. Then you get this chocolate goopy stuff come out of it. So it's broken down red blood cells. So you don't necessarily have to do emergency surgery on these, but if you get this rapid proptosis from this acute hemorrhage, then they're a problem. You need to treat them. Here you can see again, blood in these spaces. And then here you've got these, almost like pyros patch lymphocytes. And these will grow when the kids get an upper respiratory infection. So again, that can cause increased proptosis. As the plastics guys will tell you, the orbital guys, these are really tough to remove because they're not encapsulated. They send little fingers all over the place. And so if you go in there and try to remove these and you take out what you can, you can't take them all out. And oftentimes they'll just grow back just as bad. So these are really difficult to treat. So even though they're benign tumor, they can cause significant issues with the child. If they keep growing and you're getting proptosis, you can actually affect the vision with these. Here's a close-up of those pyros patches lymphocytes. So this is the lymph angioma. Now, some people will, are splitters, some are lumpers. And I happen to be a splitter. And so my brain works like an OCD brain. And so I like to have a hundred mailboxes, like upstairs and each little thing goes into a slot. But some people like to split them up. And so we'll split these up and we'll split them up among AV malformations and venous malformations. We'll split them into different categories. Other people will lump them together and say, you know what, this is all one thing. It's all just kind of this pseudo vascular anomalies. And so, you know, any kind of varices, AV malformations, lymph angiomas, they're all these variations of the same thing. And so in the old meetings we had where you'd have the orbit guys and the path guys, they would argue for, you know, hours on this. And there was, you know, letters of the editor would go back and forth for years. And so still there's kind of two camps. You know, the camp in England really likes to lump them all together in the camp over here and in Canada likes to split them all up. And so I'm a splitter, so I like to split them up. I just realized some people think it's all a big continuum of lesions. All right, what are we seeing here? Sneha. And what do you make of the age of the patient? Child. So what do you worry about when you've got, this is rapid onset, rapid onset of proptosis like this in a kid. All right, so Rhabdo's the one you really worry about. This is her scan. Now look at this huge tumor. Look at this huge tumor right here sticking out. Now, really, really, really, really big difficult tumor here. So this was a kid that when I was just started here and had this, you know, rapid onset. They did a biopsy. They said, this is a Rhabdo. We need to give you chemotherapy. We need to do surgery on here. And the mom and dad were going through a bitter divorce. Mom checked the kid out of the hospital and took her to Mexico where she had leitural treatment. So you guys are too young to remember leitural. That was the magic cure at that time. And, you know, the mean old medical establishment who likes to suppress new treatments in the U.S. wouldn't consider it. And so people go to these clinics in Mexico and they pay a fortune and they give them leitural, which is derived from the almond pits or something or whatever they came from. But at any event, it didn't work. And so they'd give them steroids and they'd give them this magic leitural. Of course it would start to shrink when they'd give them the steroids. And so in any event, dad hired a private detective, found out where mom had taken the kid, went to Mexico, re-kidnapped the kid, brought her back. By the time she came back, the tumor was twice this big. They had to do an exeneration and they had to do radiation. It was really horrible. And so these are tumors that are treatable, but you have to treat them with the right stuff. And that's the key thing. All right, so of course we've got this, we made this up for Orbit Conference once and so it's got the nice things. But tell me, what's the most common variety here, Sean, of these tumors? All right, so embryonal is the most common. And when you look at the embryonal, they'll have kind of round to oval cells. Some of them look like little tadpoles. They've got little tails on them. And so this is fortunately the one that is the least aggressive and it is the most common. Still aggressive, but there are some that are even more aggressive. So the embryonal and embryonal type. And when you look at them again, they've got these big fat nuclei and they've got these little tails that sometimes come out of them. And what do we look for in these? Mike, exactly, some striations because as the name implies, what are these derived from? Muscle. And it's not mature skeletal muscle. It's kind of embryonal muscle cells. So when you look at these, you can often see cross striations in these tadpole-like cells when you look at the rhabdomin. And you can see, you can do what kind of stain shows these real well. Trichrome, yeah, trichrome is amazing. So, trichrome will stain the cross striations. This is trichrome stain. And look at those little tiger stripes. Look at the little tiger's tail here. You can see the cross striations from the muscle in a nice embryonal. So that's the most common type. And that's beautiful. You see kind of the tiger stripes there. So fortunately, I mean, these are still aggressive tumors, but again, they're the least bad and fortunately the most common is the embryonal type. And you can do some special stains and obviously you wanna do the stains that are stains that stain for muscle-derived cells. So a desmin, bimentin, actin, muscle-specific antigen, any stains with immunoproxidized stains that stain muscle-derived tissue will stain these tumors brown. And so the immunoproxidized stain will stain them brown. All right, Catherine, what pattern is this? So this looks to go with it. It's acts with tumor cells in them. Exactly. So this is the alveolar type. So if you think about it, pathologists spend a lot of time, usually pathologians are in the basement, they're poorly ventilated, sniffing a lot of formalin. And so they get pretty imaginative. And so this does kind of look like the alveoli in the lung. And so this particular growth pattern looks like kind of alveolar spaces in the lung with tumor cells in them. Why is this important? Exactly. So of the types that you get, this tends to be really aggressive and nasty. So this is the one that you don't wanna have is the alveolar type of the rabdomyocercoma. And again, this just shows you this happens to be a muscle-specific actin stain. And so it does the immunoproxidized stain. But look at these cells. Look at the little nucleolianin. Look at that. Three, four nucleolianin, clumped chromatins of really aggressive, nasty-looking cells, and they behave that way. What do we see in here, Rachel? What would you be concerned about here? Gets. You can get. You can. That's really not, I mean, I always wanna keep rabdom in the back of your minds. But again, hoof beats, you know, you think horses not zebras. And so, you know, most common thing when you're seeing a youngster with this unilateral swelling, they may have history of a fever, maybe some upper respiratory symptoms you'd think about. Exactly. Cellulitis first, infectious or inflammatory. So what we used to call pseudo-tunamerm now, we call it idiopathic orbital inflammatory syndrome. But so you wanna think infectious, you don't wanna miss a cellulitis, especially, now this looks pretty anterior. You wanna do a scan, but if you've got a cellulitis anterior to the septae, that's not quite as bad as posterior to the septae but your orbital cellulitis. So you wanna worry about infection, you wanna worry about inflammation. And so this particular one, when they do biopsy here, what do we see in here? No lymphocytes here. So this turned out not to be a cellulitis, but this turned out to be an orbital inflammatory pseudo-tumor. So more inflammatory. Here's a close-up. You see there's the lymphocytes here. They're mostly lymphocytes. And when you look at them, they can be a mixture but a lot of predominant B lymphocytes. And then you've got, of course, the vasectomal cells and the little fibroblast proliferating around it. And here again, you can see it's very diffusely infiltrating at this point. Now, sometimes what can happen is, let's say you've had a person who's had orbital inflammatory syndrome and you treat it on and eventually it settles down. Mariana, what's going on here? I see a lot of fibroblasts all over. Yeah, in fact, even literally fibrous tissue here, what do we call this? Yeah, so the word we use is sclerotic at this point. So people used to call this a sclerotic pseudo-tumor. So sometimes when you get an orbital inflammatory syndrome, even when you treat them, as it settles down, you can sometimes get this fibro, fibrosproliferation, not really vascular, more fibrosproliferation. The reason why these are difficult is these can suck in an orbit. And so in the days before we had cortical steroids, people would go blind from these because they'd get this mass in there and they'd just get this whole frozen globe in there with this fibrous tissue around them. So it's called a sclerosing pseudo-tumor, we used to call it. So sometimes once the inflammation calms down, you can actually get even a sclerosing pattern to it. All right, Allie, what are we looking at here? A dude, I love the mustache. A external photograph. Left eye looks like it's actually got some hyperglobus. Look at where the reflex of the line is. Exactly some diffuse fullness there. And you look at the scan and again, kind of this diffuse, not really heterogeneous, kind of a diffuse lesion there. And here are the cells. What would you be concerned about here, lymphoma? So realize when you're looking at these lesions, there's a continuum. So there's lymphoma here and there is the orbital inflammatory syndrome, pseudo-tumor here. In between there's what's called an atypical lymphoid hyperplasia. And they're not just this and this, there's kind of a continuum in between and so you wanna look at things. So when you look at lymphoma versus inflammatory lesions, first of all, Allie, in lymphoma, what kind of cells do you usually see? Be what? Be lymphocytes, right? So you see lymphocytes and when you do immunoperoxidase stains, they tend to mostly be B and they tend to be monoclonal. So lymphoma, they tend to be monoclonal, B lymphocytes. Chris. Sorry, Brown. In the inflammatory lesions, what kind of cells can you see? So in inflammatory lesions, you get more of a variety of inflammatory cells. So you get macrophages, you can get B lymphocytes, you can get neutrophils, you get germinal centers. Well, less neutrophils, but certainly you can get plasma cells, lymphocytes, you know, maybe some epithelial type cells. You get germinal centers, whereas in a lymphoma, it's a sheet, whereas in the inflammatory ones, you can get germinal centers, you can get a mixture of cells. And if you do immunoperoxidase stains, they're polyclonal, they're not monoclonal. And so you wanna try to see which end of the spectrum it's on when you're looking at these. And this particular one, it's got a sheet of lymphocytes, no plasma cells in there, no follicles. And indeed, you do the immunoperoxidase stain and turned out these were all B cell capy. So they tend to be monoclonal, and that's the end where you get the lymphoma. All right, gosh, this is a really ugly specimen. What kind of surgery did this patient have here now? So this patient somewhere buried in there is actually a glow, and so this is an exenteration. So they remove the whole orbital content. So when we think of the orbit, I mean the orbit can be a repository of cells from somewhere else. And so we worry about there can be metastatic tumors that go from elsewhere in the body to the orbit, or there can be tumors that can arise around the orbit that can go into the orbit. So you can have superficial malignancies from the lids, from the conch conveyed into the orbit. You can have malignancies from the sinuses that can invade into the orbit secondarily. So what's the color here on this particular lesion? What are you worried about here? Yeah, so kind of dark, almost black here throughout the orbit. What would you be worried about here? Exactly, so this could have been a superficial melanoma of the lid or of the conch that then secondarily invaded the orbit. And when you look at it, at higher power, this did indeed turn out to be a malignant melanoma. Now, you can also have other sin malignancies, either metastatic or locally invasive. So again, the orbit, it's pretty rare that you have primary malignant tumors of the orbit itself, but it is again, a place where you get secondary tumors. And here you can see these are these big melanocytes, big, ugly-looking melanocytes. So this was a superficial melanoma. I can't remember if this was from lid or conch, then secondarily invaded into the orbit. So big, nasty malignant-looking cells. All right, this is what Sean looks like when you say it's your turn. Okay, Sean, what is this? What are we seeing here? See, I'll have a problem. What would you be concerned here? Yeah, so you can see whenever you have that surprise to look you, I just gotta think thyroid because the lids retract, the eyes get proptotic, you can see sclera above and below. And you see this injection here in front of where the muscles insert medially and terribly. So this is classic for thyroid upfilmopathy. And you look at the scan, you can see here are the muscles right here. Mike, what's the difference between a myositis and a thyroid muscle when you do a scan? Exactly, so here the tendon is spared, but the inflammation is in the body of the muscle. Now, looking at this CT scan, would this be worrisome at all? Yeah, look at those fat muscle bodies here all the way to the apex. So one of the things you worry about if you've got a really crowded, fat inflamed muscles is they can start putting pressure on the optic nerve at the apex, you can even get a scheming from these. And so this would be particularly worrisome in this case. And this is just, this is an autopsy eye. Just showing you, look at this muscle here, tendon spared, big, fat, juicy muscle here in thyroid. So when you look at the thyroid, they'll often have this lymphocytic proliferation. They'll have a lot of edema, it'll be kind of a myxoid inflammation, edema early, but late, just like some of the inflammatory pseudo tumors of the orbit, you can then get scarring. So initially you'll have edema, but then later on, if you can't call them quickly enough, you can actually get scarring and then those muscles will scar down, people will get diplopia, they won't get good movement of the muscles. All right, what are we looking at here, Catherine? That is this thing. Yeah, now what looks weird there is we're shining a bright light over here. It's shadowed a little bit there, but you see a lot of almost, you know, illumination inside that. What would you be concerned about here? Some sort of cystic lesion. All right, so this is a young child. All right, so you'd worry about a dermoid cyst. Now remember when we talked about those conch lesions, there's different, we use the term dermoid really randomly. This is what we really call dermoid. This is a dermoid cyst. So the orbit superiorly, where the, you know, bone fissures sometimes are. And so what you see when you look at this is it's filled with, what is all this stuff in the middle here? Looks like keratin. Keratin, and so when you cut these, they're really disgusting. We had a dermoid cyst yet, since you guys have been here this year. They're really pretty disgusting. They're filled with the smelly keratin stuff. It's really yucky. And when we look at the lining, what are these lined by? All right, so it's a stratified squamous epithelium that lines these and they make keratin here. What do you also have to see to call it a dermoid as opposed to just an epidermoid or dermal, you know, inclusion cyst? Well, dermus half right, what lives in the dermis? Exactly, so what the term we use is dermal appendages. So not only do you have the epithelium in a dermoid cyst, but you have hair and sebaceous glands. And so that's important so you don't, you know, don't just have the epithelium, you have the epithelium with these dermal appendages here. So that's a true dermoid cyst. And there's a close-up. There's a hair follicle, there's the shaft, there's the sebaceous glands, and there's the epithelium with the keratin in them. So when you remove these, you gotta be really careful because if you remove them whole, the kids do really well. But if they break, that keratin spills in there. Keratin can really induce nasty inflammation. So you get this granulomotus, you get these giant cells, it's really a difficult to control inflammation if these cysts break. So these are, again, something you wanna try to get out whole. And there we say goodbye to the Louvre with the fountains and the pond and the, that's the side pyramid. That's over one of the subway stations that's there. So next week we'll be tumors. And so not only is it tumors, when we talk about childhood tumors, we talk about differential diagnosis of leukocorea, white pupils. So know that for next week. And interns, now your day of reckoning is coming. So read up on the tumors, okay? All right, any questions in one minute? Nope, all right, great. Thank you. You bet.