 And so this year the ESCR's meeting was in Paris. So we started the Arc de Triomphe, which Napoleon built to celebrate all his great victories, et cetera, et cetera. But what's cool is you can go up the stairs inside here from down below. This is on top of a giant underground area where, because this has a traffic circle around it, so it's a giant underground area where there's some waste stops and people can go and there's walkways. So you can actually go up on the stairway up to the top. And so that gives you a really nice view of Paris from the top. And you can see it's all nicely inlaid with all of the carvings. And so you can imagine, you know, a grand army marching through the middle of that. And here again, you can see they always have these, these always have heroic people on the side. And there's the other side. Okay, enough said. All right, so, eyelids. Question. All right, since you're there, we said questions. What do ogre, onions, and eyelids have in common? Layers. All right, so you gotta remember, many structures in ophthalmology have layers. You guys really got to, have got to memorize what the layers are. So this is an eyelid seen in cross section, full thickness eyelid. Let's go ahead and let's start talking about the layers. So first layer on the surface. It's going to be the skin. Skin. Second layer. Muscle. All right. Chris. What's this? Conch. All right, so let's look at these layers as we go closer in, all right? First off, I guess we can go to Marshall. What's wrong with this picture? It's upside down. It's upside down, good. So every once in a while, I just want to make sure you guys are awake. So it's upside down. So usually we want to put the pathology pictures such that the anterior part is facing up and set it down. So now the anterior part is facing down. Now for extra bonus questions, what kind of stain is this? Ah, see if you guys were paying attention last week. That wasn't me last week. What's going on? Huh? Trichrome. Trichrome, very good. I didn't know where that was good, all right? So. How should I say it? Trichrome is an interesting stain because of course it stains for a reason for the corneal dystrophies and so corneal stromodystrophies. But it stains epithelial tissue red or pink, if you will, but also muscle tissue. It stains connective tissue blue. And so it's a nice way to say it. So again, here's the surface epithelium. Here's the oboecularis oculi muscle. Here's the tarsus, it's connective tissue. And then lastly, corneal, the palpibro, so the congenitiva, the palpibro congenitiva, and then the cornea, underlying it. All right, so when we look at the skin, tell me about the skin on the eyelid. It's carrotinized. Okay. And it fights squamous because there's layers. Shuffle squamous. How is skin on the eyelid different than skin elsewhere on the body? Exactly, so there's no dermis, and so there's no dermis underneath there, but also there aren't the reedy ridges and pegs. And so if you look at skin elsewhere on the body, there are those reedy ridges and pegs, and then you have the reticular dermis and the dermis with the fat underneath it. And so when you look at eyelid skin, there is no dermis. There's no fat while except, you know, old guys at the VA, there's fat underneath their skin all over the place, but there's no fat underneath it. There's no reedy ridges and pegs, so it's a stratified squamous. Carrotinized epithelium. Very similar to skin elsewhere, except it doesn't have the underlying tissue that it has. And in fact, the tissue underneath here is kind of a loose connective tissue and what that allows is that allows, if you have, for example, an allergy or a reaction to something, you can get a tremendous amount of edema in the eyelids. And so there's a lot of edema that can occur there, okay? And then, Brad, what layer is this now? So is that the, like the sub-epithelial layer? No, look closer. This is the sub-epithelial layer here. Okay. Oh, is this a subcutaneous fat? No, no. What's the next layer down? Oh, we've got muscle. Muscle, which muscle? Obicularis. All right, so this is actually the obicularis muscle. So you wanna keep straight the difference between what the obicularis does and what the levator does. So remember, the levator comes out superficially and then inserts into the tarsus and helps to lift the lid open and close. The obicularis sits underneath the skin but in front of the tarsus and the obicularis runs this way. And so when you look at the obicularis, the obicularis has three parts to it. Okay, so chance to save yourself. What are the main parts of the obicularis muscle? So we have the oculi, preceptile, and sep... in tarsus. Kind of sort of. Obicularis oculi. Obicularis oculi is the whole muscle. And what was that? The obicularis oculi is the whole muscle. But there's three parts. So there's pre-tarsal, the obicularis closest to the eyelid margin in front of the tarsus. There is the preceptile. The obicularis that's out a little bit further peripheral in front of the septum. And then there's kind of the orbital part to it. So if you think about it, it's three concentric bonds. And it almost looks like a C as it comes around when you look at it. And so the obicularis doesn't open and close the eyelid, but it keeps the lid against the surface of the eye. It keeps it from flopping all over. And it runs this way, where the levator runs this way. Okay? All right, what layer are we looking at here? I guess, Richard, we come back to you. So you still get all the layers, but I think you're focusing on the tarsus. There's that. Tarsus, okay. So tell me what is this tissue right here in the tarsus? What kind of tissue is that? It's a dense, fibrous, connective tissue, very dense. Now, how is the tarsal plate different in primates as opposed to lower animals? It doesn't have cartilage. And so if you ever do surgery on rabbits, you flip their eyelids, it's really tough. And it's got cartilage in it. And rats, same thing, you're doing research with rats, it's got cartilage in them. Primates do not. So we don't have cartilage. It's a dense, fibrous, connective tissue. But again, when you flip a human eyelid over too, it really gives body to it. I mean, it's pretty dense, connective tissue. All right, Mike, what is this stuff right here? All right, what kind of glands? So they're the mypomian glands. Exactly, those are mypomian glands. And if you look, the way I like to describe these is they're almost like, if you ever look when they grow grapes, how there's clusters of grapes, and then they cluster around a vine. And so there's the grape clusters here with the glands, and then there's the vine in the center, okay? All right, this is a good segue into a topic that everyone just loves, and you guys are gonna know these by heart. Glands, all right, now, the nice thing about the iMid is the iMid has all three major gland types. All right, so Chris, what kind of gland are we looking at here? Type of gland, clasp of gland. I think these are eccrine glands? Echrine glands, all right? And so how do we characterize eccrine glands? Well, that's one of them, but what pattern do we see that tells us these are eccrine glands? I'm not sure. They have a pattern that's called an asinine pattern, and what means is it's not that makes an ass of i when you guys don't get this right, but asinine, so they form these little round structures, and basically what the glands do is they secrete their contents into this little lumen, and then eventually it gets gathered up into a duct and secrete it, and so the gland stays intact. It secretes its context into the center, and if you look real closely, there'll often be little secretory granules here in the cytoplasm. So in the eyelid, we've actually got a couple different types of eccrine glands. What are a couple of eccrine glands that live in the eyelids? So we've got lacrimal glands? Lacrimal glands, so that's a classic example, but what else that you don't usually think about in the eyelids? Sweat glands. Sweat glands, so believe it or not, your eyelids can sweat, and I know that's hard to believe, but eyelids can actually sweat, and so you actually get sweating eyelids, and so these are the eccrine glands, the asinine type glands in the eyelid. All right, now this is the lid margin, and what's good about the lid margin is the lid margin can illustrate several different types of glands, and so the first type of gland that I wanna talk about here is this gland right in here, and if you look, here is an eyelash follicle, and if you look at the base of the follicles, you'll see these glands right here, and if we look real closely at them, Ali, this is the third, this is the second type of gland in general, what type of gland is this? Apricot gland, okay, and how are these characterized? How do we know they're apricot glands? They're associated with total lash or follicles. They have snouts exactly, so if you look at them, they have these apical projections. They look like little snouts sticking out into the lumen, so when they secrete, they secrete their special product, and they actually almost cut their little snouts off, and so you see those snouts going into the lumen. Now, why do we stress snouts? Because it helps us to remember the name of the apricot glands in the eyelid, which are the glands of mole, but we mispronounce it as the glands of mole. Why? Because moles have snouts, and so that's how you remember these. So the glands of mole have these snouts, and they do this apricot secretion. This is a very interesting secretion. It's probably a remnant from far back in evolution, because these are senting glands, and so you have them, and for some reason in the eyelashes, you have them in the axilla, you have them in the groin, and so they're a senting gland. Some animals like deer have very developed apricot-type glands that are there, because if you ever notice deer, you'll see them they'll rub their eye inside of their eye on branches, and it's a senting thing. So they actually use it to mark, as opposed to urinating and other things you can scent, and so this is kind of a remnant-sending gland. We really don't know, it doesn't really do much in humans, but it's still there. And so this is the example of an apricot gland of mole. All right? All right, we'll do the gland. You're these here, Marshall. All right? So these are an example of sebaceous glands. In which class are they? What's the third class of glands? Pile of sebaceous. Main class. Others think sebaceous glands are... Holocrine glands, all right? So they're Holocrine glands, and so the way you remember Holocrine glands, they give their whole cells up when they go into the lumen. So instead of being like echrine glands where they stay intact and just squirt some stuff into the lumen, these guys squirt their whole contents in them. And so it's a Holocrine gland, and their whole cells just regurgitate in there. So for those of you who partake in the two-carbon chain disease when you're in college, sometimes you have a little bit too much of that, and boy, sometimes all of that Holocrine, all your intestines are all coming up and out. So that's the time when you also get religious because you pray that, oh, God, get me through this and I won't drink ever again in my life, I promise. So these are Holocrine glands. They regurgitate all of their whole contents into the lumen. And so the example of these are sebaceous glands, and in the eye specifically, the mybomian glands. But we skipped over another type of sebaceous gland, all right? Dr. Jacobson, what is this gland right here? So it's associated with a hair follicle. All right, what's it? Gland is that called? That's it. Like, are you talking about like the overall class or the individual gland? Both, okay. So it's a Holocrine and it would be like a sebaceous gland. And? And what's it called? This is the gland of Zeiss. And so Zeiss glands are a specialized Holocrine gland that are associated with the hair follicle. So they put this greasy Holocrine material on their slide. You know, you often have pylosebaceous glands associated just with your regular hairs, that's where in the body. And so they put out the sebaceous material, but in the eye, you have with the hair follicle on the hair shaft here, you've got a gland of Zeiss. And so there's two different kinds of sebaceous glands. You've got the sebaceous glands that sit in the eyelid, which you've also got the glands of Zeiss. What kind of stain is this? Let's go back to Rachel. Nope, nope, not quite. So why would I be showing you this? I mean, here's the previous slide. There's those glands, and then I'm showing you this. Oil-red-O, exactly. So it stains lipid. The lipid stain oil-red-O. And easy to remember it, because it stains the oil, all these little round O's. You know, so oil-red-O stains and rat. What's important to realize before you do an oil-red-O stain, what do you have to do with the tissue? Exactly, it has to be fresh. And so if you want to do an oil stain, you cannot process it, because for normal processing, we leach out all of the oils during our dehydration and processing. So if you want to do an oil stain like this on a mybomene gland, you have to have fresh tissue. All right, so everybody set on glands. Okay. All right, let's look at some eyelid lesions here. What are we looking at right here? Exactly. Ptolemnolated, enter chamber, IOL, PI. They'll just diffuse. Look at those little vessels here. Just diffuse mybomene gland disease, mybomene gland dysfunction. So anything alarming about this lesion? There's a certain, there's still lashes there. So no lash loss, no notching, no diffuse thickening all around there. So this is maybe one that shows it just a little bit better. This is a younger person and you can see these. What do you think these lesions may be? They look good. All right, so let's see what the path showed. It's all... Exactly, big giant cell here, as opposed to small giant cell, I guess. Big giant cell. And what do you think all these little wide areas are in here? It's like a lipid. Yeah, so dissolve lipids. So what do you think that lesion was? Exactly. So I guess I don't know, is it the proper term? Is it Kallazian? As opposed to Shalazian? I'm not a language scholar. I think it is Kallazian, so. But in any event, what happens is, is you get one of the mybomene glands gets plugged up and then you get backup of lipid, insipidation and then it's not infectious, but it causes a lot of inflammation. So you get this lipogranulomatous inflammation and that's the most common thing that you see in a Kallazian. And here is it. Now this is a big giant cell, as opposed to a little giant cell. So believe it or not, that's all one cell here. So giant cells, again, all these lipid vacuoles here, so there's a lot of backed up lipid and then giant cells. You also can get lymphocytes and plasma cells with these also. And so that's probably one of the most common things we see in the clinic is a Kallazian. Very satisfying. And if you drain those, I don't know if you guys have had a chance to drain them, but it's pretty cool, you flip the lid and you put the clamp on there and you get in the right place and you go on with your blade and you go, it's like a giant zit. So a lot of, very satisfying. All right, Chris, what is this? So we've got an external photo. There's a large flasco deletion, the lateral part of the upper lid. There's no motorosis, there's no notching. There's not even a lot of ptosis from it. It's kind of cystic and naturally. Exactly, so this looks more cystic than it looks solid. What's that little test you can do in two seconds in the clinic to see if it's cystic? It's not transilluminated. Exactly, so you take your little fat off head and you put it right next to it and if it is cystic, it'll transilluminate. If it's solid, it won't. And so this looks like it's a cystic lesion. And what's the most important layer of a cystic lesion we look at? The lining. So this is at low power. So what can you tell me even at low power here? So low power, there's multiple layers of the lining to stratified, I'll be squamous because there's a lot of, looks like keratin material in the center. Exactly, so you've got this stratified epithelium. There's a lot of say, morpheus infilataining material consistent with keratin. So this would be. It's been epithelial inclusion. Epithelial inclusion cyst. And this is the most common cyst that we see. And by inclusion cyst, they mean a piece of epithelium got placed underneath the skin for some reason. So it can be trauma, it can be previous surgery, but for some reason surface epithelium gets underneath and then it grows and grows and grows and makes keratin. So when you remove these, you really want to try to remove them whole because if the keratin spills out, keratin is very inflammatory and so if you break these and the keratin spills out, you get a tremendous amount of inflammation. And so epithelial inclusion cyst is the most common. Here's a close-up again. All of this keratin, kind of these whirling concentric rings of keratin. All right, and here's the close-up. Stratified squamous epithelium. All right, Allie, what are we seeing here? It's flesh colored. It's hard to, I don't think there's lashes or, you know. Okay. They're mesistic. And again, if you look at it, you just get that idea that it's kind of smooth on the surface and there's something inside growing, pushing it out. So likely this is also cystic. And so again, the most important layer we need to look at, the lining, the lining of the cyst. Okay, here's the lining. What do we see in here? Cuboidal, one to two cell layers thick. What is this? D-note. Exactly. And it's an eccrine-derived hydrosystem, okay? So hydrosystem, what language is that from? From the Greek, of course. Hydro, water, cysts, that's water-filled cysts. So from the Greek. So hydrosystem, so this is a bi-layered cuboidal lining and it looks almost like the ductile lining from an eccrine gland. And so these probably are eccrine-derived cysts. So eccrine, hydrosystem of the center will be just empty or with fluid. So basically just eccrine secretion. So sweater or lacrimal secretion. I thought these were pseudoriferous cysts from the Latin. That's the other name, pseudoriferous cyst, not from the Greek, from the Latin, but that's an altar, altar. So you remember the Romans, the Latins, they took from the Greeks. The Greeks first did it and then the Romans, they just took it from the Greeks. Okay, all right, so what do we have that's different here, Marshall? It looks like the lining of this cyst-like structure has out-pouchings. Yeah, this lining has nuts in it. So what would this cyst be? Driving from gland to mole. Well, exactly, driving from an epichrine gland. So if you have eccrine hydrosystems, believe it or not, you can have epichrine hydrosystems, much less common, but same idea. So it's lined by this bilayered cuboidal type lining, but it has snouts on it. And so apricrine hydrosystem, and not eccrine hydrosystems. All right, what do we see in here, Abby? All right, so what do you think looks like this? All right, Moluscombe, exactly. So I've stolen one of the sayings of an ocular pathologist who's probably 90 now, but Ray Fawn was the ocular pathologist at Baylor. And his favorite saying when something was classic and nothing else looked like it. And he's from Cuba, by the way. And so he would say, you show a brother in the train station. And so I say, what the heck does that mean? You know, you go to the train station. What do you see? You see 1,000 people. How do you know your brother? Because only your brother looks like that, you know? So you show a brother in the train station. So what that means is nothing else looks like this. This is, classically, your brother in the train station. And so when you have multiple clusters of these raised pearly edges, umbilicated centers, this is Moluscombe conciosa. And similarly, you show a brother in the train station. Nothing looks like this pathologically. So how would you describe this? So heavily keratinized at the top. And there's kind of these clusters that are with eosinophilic eruptions. All right, so you see very thickened epithelium. You see it's kind of elevated at the edges, umbilicated in the center. And when you look at these at a higher power, you see what are called Moluscombe bodies. What the heck are these? Exactly, so the virus takes over the cell, literally. And it pushes the nucleus to the side. And eventually, when you get to the top, all you're left with is just a sack full of virus. And so these Moluscombe bodies are just eosinophilic staining full of virus. And you see what happens is they spill out on the top, which is why these come in clusters. Because the virus is spill out. And then instead of one, you get eight or 10 of these. Now the nice thing about these is when you wanna remove them, you can just shell these things out. You just scoop right out. And so, but there's usually multiple ones. So Moluscom conciosa. All right, Brad, what are we looking at here? This is an external photograph of both the left and right eye. And in the superionazole quadrant of the upper eyelid, we see this kind of nodular lesion. It looks to be no surrounding like erythema. There's no ulceration. It looks like it's filled with some sort of substance that's giving it this yellowish hue. What do you think this could be? Xanthalasma. Exactly. So this is classic Xanthalasma. It's got kind of a yellow plaque-like lesion. And what does it characterize by pathologically? So it's lipid-filled. Lipid-filled what? What kind of cells have a lipid in it? Macrophages. Macrophages, exactly. So if you wanna sound intelligent, you say... Macrophages. Macrophages, you say with a British accent. So people think you're smart if you speak with a British accent. Macrophages. And so if you look at these, these are all foamy, lipid-laden macrophages in the subepithelial tissue. Now when I was a resident in the olden days, they taught us that this meant you have hypercholesterol and that you had to do blood tests and people had a chance that they had hypercholesterol. Is that necessarily true? No. So it can be associated with hypercholesterol, but it doesn't necessarily mean it. So something focally is going on and you get this deposition of this cholesterol material in these foamy macrophages underneath the skin. And so not necessarily associated with hypercholesterol. Here's a hyperview. Look at these, they call them foamy. And so you see these macrophages, they've got the nucleus in the center and this foamy, ground-glassy lipid material in the cytoplasm. So that's classic xanthalasma. You know, I don't mean to not call on you if you would like to try one you can. It's up to you. It does up to me a little bit. That's really not a positive thing. Yeah, bring it on, man. You know, it was kind of a, okay, I'll do it. Well, just describe what you see down. Tell me what you're seeing here. Flesh color in and out. Remember we showed you all the cysts and they were really smooth and like something was inside pushing out. If you look at this, it's almost corrugated here on the surface. We think that could be. And that's fine. I mean, that's a good answer. I don't know. I was okay. I knew the last one was okay. I knew the last one was okay. Well, it's interesting. We always know the answer when we're not being called on. So everybody's like, oh, oh, oh, oh, oh. And then as soon as the spotlight hits you, it's like the iron curtain, the scents across your cerebral cortex chunk and you're like, what's your name? Yeah. Rachel, what is this? Exactly. So it's a papilloma. It's got that little corrugated, almost like a little cauliflower appearance to it. So this is a squamous papilloma. And if you look at this at low power, you've got these fingers of thick and acanthotic epithelium sticking out. And then they've got a little fibrovesicular core in the center. What's all this stuff? Keratin. So there's hyperkeratosis. There's a lot of keratin on here. So how do we remember a squamous papilloma pathologically? It's a gloved hand. So you've got a hand with a thick glove on it. So you've got the central fibrovesicular cores and you've got this thickened epithelium surrounding it and it's sticking out. And so you can see again here, these fingers are sticking out in these little fibrovesicular cores in the center. It's hyperkeratotic. And so this is a classic squamous papilloma. It can't be viral. It can also just be just reaction to whatever. Sometimes there's no viruses in it. Here's the close-up. Central area of the fibrovesicular core, thickened acanthotic epithelium, hyperkeratosis, increased keratin cell layer, all in the surface, tons of keratin. So squamous papilloma. Can you see pathologically if it is virus associated? You can't tell pathologically, but if you study sometimes they'll find virus most of the time they don't. When you said like the moluscombe, you can scoop out. Do you mean like? Moluscombe, you can literally numb it up and use the side of a needle and just go, and they'll just like core out. Okay, you can leave a little bit of it. Well, yeah, it's a little bit of a divot when you do, but it'll core out. With these you actually have to remove them at the base. But sometimes it can be pedunculated and so you can actually just cut them off right at the stock and they'll come off nicely. And this just shows you a little bit of a closer view. Here's they even will get little keratin filled cysts in them and little crypts with keratin in them. And here we see a cross section. So this is where someone you took your gloved hand and you just cut the fingers off right across. So here's the fibrovascular core in the center. There's the epithelium surrounding it. All right, what do we see here? So this is a closeup of a kind of waxy, darker colored lesion. There's kind of multiple parts to it stuck on. Yeah, what do you think all this crusty stuff is here? Probably keratin. Probably keratin. So these are hyperkeratotics. Oftentimes you'll see these guys in clinic, you'll say, how long this lesion been? I say, well, it was there a few months ago and then it fell off, but then it grew back. And so what they're talking about is just the keratin comes off. And you see these guys, people pick at them too. And so they'll often pick the keratin off but the underlying lesion will stay on there. All right, so how is this? It looks almost like the papilloma but what's different about this one? Exactly, so instead of the fingers going out, it's almost like they turn over and go in like a hairy spider. And so instead of the fingers going out, they go in. So it's like a tarantula with multiple legs and hair around them. And so here's the fibro-vascular cores but the fingers of acanthotic epithelium are extending in instead of out. So that's the difference. So this is a... Separic keratosis. Separic keratosis. And so it also has hyperkeratin. It can have keratin-filled crypts. It can even have keratin-filled cysts that you can see right there. And now the other thing that these have is they'll often have a brown coloration to them. So they'll often have some benign melanocytes along the basilar layer. And so when you look at these, these aren't active. They'll just benign melanocytes on the basilar layer. And so it's not uncommon that you'll have this diffuse ribbon of brown on the basilar layer. So when you look at these, they'll look tanner, they'll look brown. This is a classic Separic keratosis. All right, what are we seeing here, Chris? We're seeing the lesion, not a sexual photo but we're seeing the lesion just below the lower lash line. It's kind of rough on the surface, maybe a little bit flesh color to yellow on the surface. There's no maderosis and there's no nodule, any mass. Kind of almost Separic keratosis looking, hard to tell, so we look at the path. Now the difference in this one is, again, it's hyperkeratotic. It's got the thickened acanthotic epithelium. It's got a tremendous amount of what we call basophilic degeneration of collagen. So these are usually in areas where there's a lot of sun exposure, basophilic degeneration, but if you look at the epithelium itself, the epithelium is more active. And so here's, again, keratin world down below, keratin in the cells. Boy, my fellows are never here so I can insult them. But obviously a fellow took this picture. Why? Because it's out of focus. So the attending pictures are always in perfect focus. That must be the fellow that did this. And so that's the other thing. Whenever I show videos, if it shows beautifully done, I say, okay, this is me doing this. If it shows a complication, I say, well, obviously this was the fellow doing it. So we get to say that. So this is what we call actinic keratosis. And actinic keratosis is kind of a Separic keratosis gone one step further. So it hasn't quite become a malignancy, a squamous cell, but it's starting to show funny features. And so you'll have nucleoli in here. You'll have more activity of the sounds and you still get hyperkeratosis, keratin pros, keratin ones. So this is called actinic keratosis. Now, what do we see in here? I don't know. There's a lesion that's ulcerated, which is really obvious, but then there's like a raised, which looks like raised border kind of pearly. And it looks like it's a facing lashes and which is concerning. All right, so this is worrisome. Because you've lost lashes. You've got, now where do you think that lesion ends? Here? Here? Yeah, so if you look at it, boy, that thing maybe takes up 70% of the entire lower layer. So when you see a lesion that's ulcerated in the center, it's a little bit raised on the outside. You've lost lashes. There's maybe thickness next to it. What's your concern? Basal cell? Basal cell. And so this is a pretty classic, not quite your brother in the train station, but maybe your second cousin in the train station. You think that's him? But quite sure. So that this is really a suspicious appearance. And so this is another way these can present. Because remember, they're always not all classic. And so this, if you look at it, looks almost kind of a solid, maybe even a cystic lesion. But again, look, loss of lashes. Look at the notch. So same thing here. Same idea here. And we look at the path. Does this confirm it? Okay, so we've got these nodules of the tumor cells. They have this dark basophilic staining nucleus, a scantycytoplasm. But again, the classic finding here is that the nuclei line up around the edges of the lesion. They call it palisade. So this is classic for a basal cell. Now basal cell, the most common type of basal cell is called a nodular or nodular cystic. This would be a nodular basal cell. We look at a closeup. Once again, large nuclei lining up around the periphery of each of these lesions. Now the other thing that you see is, you see this little white space here? We call that a meaningful artifact. And by that, I mean, it's an artifact. It's tissue shrinkage during processing, but it occurs in basal cells. And so for some reason, these basal cells are more tightly packed in there. And as you process the tissue, they shrink a little bit more, whereas other tumor cells don't. And so you'll often see a little white halo around each of these nodules of the tumor cells. So we call it a meaningful artifact, because it really only does that in basal cells. All right, so here again, we see a nodular cystic basal cell, most common variety of basal cells. All right, now, Marshall, there is one type of basal cell that's a little bit different that we worry about more than run-of-the-mill basal cells. What is this? Morpheiform. Morpheiform. What does that mean? I mean, why is that different? It's usually flatter. It sends out finger projections underneath the skin, so you're worried about more extension of the tumor. Okay, so if you look at it, it's characterized by these little fingers of tumor cells. And then in between, you have this dense connective tissue. They call this desmoplastic reaction. The problem with these is they're not a localized nodule. They can send little fingers out underneath the tissue. So it's very hard to know what your margins are. And so if you are concerned about a morpheiform type of basal cell instead of just removing a chunk, you may often refer them off for what's called Mohs surgery. Now remember, Mohs, it's the guy's name, M-O-H-S. It's not, you know, Mo, you know, M-O-E, you know, Mo, woop, woop, woop, woop, woop, woop, woop, woop. You guys don't even know the Stooges? My God, I know this. They weren't even around when I was little. That's how old they are, but the Stooges, Mo, you know, woop, woop, woop, woop, woop, woop, woop. So, that's what, really. It's not Mo, yeah, that's Curly, but my favorite with Curly is Mo, that's good, but Mo, and Mo, you hate this now, because you can't show this to kids anymore, so Mo would poke Curly in the eye with his fingers, and he'd go, and so, so Curly would go, yeah, and then Mo would go, so. So not that Mo, but Mo is the surgeon, M-O-H-S, and so there's a way you can remove the tissue, taking little fresh pieces of tissue, you freeze them, you look out of under the microscope, so that's the most technique. So you do that in a, in a Morphea form. Now, there is even another way that these basal cells can present. What does this look like? I see the classic palisading in the base, but more inferiorly, there's more of a pinkish coloration and where you're pointing over there was kind of like a keratin, pearlish type of thing. Exactly, so what is this? The combination of the two. Yeah, it's actually, they call it a basal squamed, and so you can even get, you know, basal cell carcinomas come from the little pluripotential cells in the basal layer of the epithelium, and so they actually even call these basal squames, and so they can even start to show some squamous characteristics, and so the reason why this is important is these again are more aggressive than a run-of-the-mill basal cell. So regular basal cells, you know, you remove them, they, you know, you take care of them, that's it, they go away, but morphia form or basal squames, you worry about them because they can be just a little bit more aggressive than a run-of-the-mill, and I always show this picture. This was one of Rick Anderson's original patients. This is a tough old ranch lady from Nevada. She had a morphia form, and they said, you know, come back in because this thing can spread, we better take care of it, and so she said, I'm an old lady, leave me alone, and so she went back to the ranch, and this is 10 years later, and the reason that she came in her family brought her in because of this smell, and so you can see a basal cell left on its own for 10 years. If you look back here, it's growing into the sinuses, there's even CSF dripping out here. So you say basal cell is a benign tumor, but if you let it grow for 10 years, it can do this, so believe it or not, this was a basal cell let to grow for 10 years. Now, what do you do? I mean, you can't do a hemi facectomy, and so this is a really difficult problem at this point. So take care of the basal cells when you can. All right, Brad, what is this? Yeah, so this is an external photograph of the, gosh, maybe left eye, and on the lateral lid margin, you see this large nodular lesion that is causing some adorosis at the lid margin. It's got, like, it looks like some hyperkeratosis and maybe some small central ulceration as well. What would you be concerned about with this one? The squamous cell. Yeah, because this has like a lot of keratin on it, but it's got almost kind of an orangish appearance to it. And so indeed, there's another way that these can present like this. And so it's interesting, they call it a rodent ulcer, and I don't know what rodent means, it must mean something, but I think of it as rodent, it means like a rodent's been chewing on it. So rodent ulcer, the way I remember it is, a rodent's chewing on it. So you'll often see these will present, look at this patient, this is sun exposed skin, probably a pharma rancher, again, a lot of sun damage, and sure enough, here it is right here. So when we think of tumors of the eyelid, basal cell is by far the most common, at least 90%. So if you take all lid tumors, basal cells, 90%. Squamous cells, maybe five or 6%. And so basal cells are totally sun exposure related. And so they occur on the lower lid, medial canthus. They occur less frequently on the upper lid laterally, why, because your brow shades that. And so some of us, let's see who's more chromaginous, you sure are chromaginous in here, a little bit bigger brow here, so it shades a little bit better, and so we get that. But squamous cells on the other hand can occur both upper and lower lids. So they're still thought to be sun induced, but not quite as much. You can get the nodular type again, or you can get this rodent ulcer. And what is the squamous cell characterized by? Hyperkeratosis, and like mostly like pink rather than like the basal cell, which is kind of like the purple-ish. Or the blue, yeah. So this is more pink than blue. You look at the cells here, they tend to be pink. We look at them closely, and not only do we have these pink cells, here's the nucleoli again, they're active cells, but what are these guys? Keratin worlds. Keratin worlds, so you get keratin worlds in these squamous cell carcinomas. So you get these keratin worlds in there, you have the big, atypical pink cells as opposed to the blue cells. So this is a classic squamous cell. All right, I guess we're coming back to, do you want to try it? Sure. What do you see in here? Sorry? Do you want to give it a shot? What do you see in here? The coloration of that. Looks like bleeding. What would your concern here be? Actually, well, the problem is this is what we call the great mimiker. And so these, you often do not see these initially. You'll see them second or third hand. So first thing, the person goes into the dock in the box. You know, they go to the, you know, whatever they call it, the walk-in emergency center, you know, dock in the box. So what do they do? They give them neosporin. They say, I'll put a little conjunctivitis, give him neosporin. It doesn't get better after two weeks. They go to another family dock. What does he give? He gives them genomycin. It doesn't get better after two weeks. Finally, they see you. But if you look right here, that lid margin is really thick. And there are these little yellow areas here. And look at the lashes are gone. Same thing here. Thick lashes gone, chronic blepharoconjunctivitis. What's your fare here? Sevation cell carcinoma. Exactly. So this is a sebaceous or mybalmine carcinoma. It's called the Great Mimiker. It can look like a blepharoconjunctivitis. It can look like a recurrent chalazion. And so you really have to have a high index of suspicion. But if you look, this is not just blepharoconjunctivitis because the lid margin is thick. And you're losing lashes here and you've got all this lipid in here. So this is a classic diffuse sebaceous gland carcinoma. But again, they can present a little bit differently. Look at this one. This was called a chronic chalazion. But if you look again, look at that lid margin. It's thick from here to here. And so this turned out to be a sebaceous gland carcinoma of the lid. So when you look at sebaceous gland carcinomas, the one thing nice about lids is lids, the pathology kind of looks like how they behave. So you look at the basal cell. Those nuclei look kind of benign. You know, they're uniform. They're not on nucleolide. They're big, but they're benign. You look at these nuclei. Boy, clumped chromatin all over the place, nucleolide all over the place. You look at that. Even if you don't know pathology, you say, wow, that looks really nasty looking. And indeed, that's how these behave. Fortunately, these are only about 1% of all lid tumors. But you got to recognize these because these can not only invade locally, these can distantly metastasize. People can die from these. So you really want to recognize these. And if you look right here on this close-up, look at that clumped chromatin. Look at the nucleolide. What the heck are these things here? Those are mytotic figures. So there's mytotic figures. So we have one of the neuropath peoples rotating with us in path. And I love that pathologists said it in this term because of mites. And so, real pathologists, I'm not a real pathologist, I'm just a humble ophthalmologist, but the real pathologists call mites. So there's mytotic figures all over the place here. So these are very, very aggressive tumors. And here again, look at that beautiful mitotic figure there. Look at these. Some are big, some are little. What do we call them when some cells are big and some are little from the Greek? But polymorphism or pleomorphism, either one. So different size, different shape, exactly. So polymorphism, pleomorphism. So lots of that. Big nucleolide, a big, I'm sorry, mytotic figure, big mites right there. So very, very aggressive tumors. You don't want to miss those. What kind of stain is this? Oil red-o. Oil red-o. Okay, just to again to show you that we don't really do this anymore because we can do specialized immunoperoxidic stains. But again, oil red-o. All right, that didn't count. What is this? What are we seeing here? So this is an extra photograph. The polymorpholide has a pigmented lesion. Looks like there's still lashes there. The lip margin looks relatively intact. So I would guess benign. All right, so probably benign and you take it off, what is this? So you got some nests of cells. I would guess that this would be a nevus. More specific? Looks like it's at the junction, also in the dermis, so compound. Exactly, so when you write nevi, if they have a component of the melanocytes at the junction, we call that a junctional nevus. But if you have nevi at the junction and in the subepithelial or dermal tissue, we call that a compound nevus. What is this? So this one looks like it would be a dermal. Exactly, so if you look here, the melanocytes are not at the junction. There's a clear space, they're underneath it, and so we call it a dermal nevus. Now, remember there is no dermis in the lid, and so it's kind of a misnomer. It should be called a subepithelial nevus, but because dermis has been around for 100 years, we've been describing it, we call it a dermal nevus. So no junctional component, dermal nevus, completely benign. All right, what do we see in here, Chris? It's external photo. There's a much more extensive pigment of lesion in the lower lid. We see definite materosis there. I'd be concerned about malignancies. Yeah, she'd be more concerned about this one. And if you look right here, first of all, these look kind of benign. You're looking at your same one. That's benign, looking, but then you look closer, and what do we see here? Look at those nucleoli. Look at the cells there. So indeed, this is now a malignant melanoma. And now these, again, you wanna recognize these can metastasize. They can invade locally, they can metastasize. So these can be bad actors. Unfortunately, the incidence of malignant melanoma that lids is going up. Why? Because the baby boomers were, among all of our other bad traits, sun worshipers. And so you had that golden tan and it made you look beautiful and glow. And so now, as the baby boomers are getting older, we're seeing tumors such as melanomas now increasing. So they shouldn't be. So I guess I'm behind the times. I finally was reading about how the derisive term that the millennials now use, where you say, okay, boomer, you guys do that. So if I start yammering on, you guys are allowed to say, okay, boomer, and roll your eyes when we say that. But this is one thing that is really bad about the boomers is all the old sun exposure that we used to have. And so we are seeing more and more malignant melanomas of the lid. And so you guys are gonna see more of these when you're out seeing patients out in practice. All right, what the heck is this? And your first thought is, wow, maybe someone's got a preceptile cellulitis. They've got a big swelling here, but it's not really hot. It's not really infected. And so you go ahead and do a biopsy and this is what it shows. What kind of cells are these? Lymphocytes. Lymphocytes. And if you look at them, they're medium-sized, uniform, lots of them. But again, slowly clear lying in here. So what is this? So lymphomas. So now lymphomas of the orbit are much more common. But remember, you can get lymphomas of the lid. Less common, but keep that in mind that when you're talking about lid tumors, they're very rare, but you can still get lid lymphomas. Usually the lid lymphoma is an extension of orbit lymphoma, but you can still get lid lymphomas. All right, my marshal, what are we seeing here? It's an external photograph showing both eyes. For the left eye, the eyelid looks 30% eroded, especially nasally, and there's a round red circular lesion right in the center. Yeah, people call this violaceous. It looks kind of a deep red, red-blue, kind of a violaceous-looking lesion. All right, so now I just wanted to show you guys a couple of obscure ones, just so you know now all things are common. Hopefully something like this will never show up on the boards, but every once in a while, they'll toss one in. So old person, big violaceous lesion here. And if you look right here, big cells, but lots of mites in here, lots of mites, big cells, lots of mites. Believe it or not, this is called a merkle cell tumor. And so you can get these, they thought to be uprising from parts of nerve, sometimes nerve endings, but you can get the old people, violaceous lesion, lots of mitotic figures in here. This is called a merkle cell carcinoma. You could even get adenocarcinomas of the lid. Very uncommon, but this is an adenocarcinoma. And the way you remember these is you've got these islands of these little glandular cells swimming in a sea of mucin. So this is a mucinous adenocarcinoma. And again, it gives me a chance to show special stains. We actually have a mucin stain. It's called mucicarmine, very rarely used. So I didn't make you guys memorize that. But again, islands of adenocarcinoma cells swimming in a sea of mucin. So these are just weird tumors. So merkle cell tumors, adenocarcinomas, mucinous adenocarcinomas, very weird tumors. Hopefully you'll never see. But you've got to know basal cell, squamous cell, sebaceous and melanoma. So if you know those and know those down, you'll be okay for not only boards, but more importantly for practice. All right, I think that's it. Okay, so again, this is looking from the arc de triomphe out outside of downtown. This has got a lot of defants and it's got this big concrete thing around it. So this is where they've got a lot of tech businesses live out here. Where is that? Paris. Wow. Yeah, so this is out. So you know that the center is really ignoring. But you still have to make, I mean, history is great, but you still, people still have to have jobs and do things. Man, that's crazy. So yeah, that's Paris. I've been here for like 10 days. If you look out here, I just love this building. Well, believe it or not, this is the extension of the Champs-Élysées right here. All the way out, so it goes around the circle of the arc de triomphe and you go out. And it's a lot of fonts, this is called. So like downtown is this way, either way, up far. I just like literally like all the history. Oh, I'm standing on the top of the arc de triomphe. Yes, no, I mean, you could see downtown the other way. Yeah, exactly. It's not like that. That's next week. Next week, hold on, hold that thought. All right, so next Tuesday is? Conch. Conch. All right, so everybody, read your comment.