So, this is Dr. Booth. Dr. Booth is a pathologist, an expert GI pathologist in esophageal disorders. He's at Northwestern. He's calling live from downtown on the Magnificent Mile, and will be giving us the pathologist perspective of EOE. Dr. Booth, you good? I'm good. Thanks. All right. Thank you so much. All right. Well, good morning, everybody. I'm looking forward to talking to you a little bit about my perspective as a GI pathologist on eosinophilic esophagitis. As he mentioned, I'm an assistant professor of pathology downtown here at Northwestern in beautiful Chicago. With that, let's get going. Just a few objectives for our talk here. We want to outline the differential diagnosis of intraepithelial eosinophils. For me, as a pathologist, whenever I put the slide down in the microscope and I see eosinophils in the intraepithelial cells within the squamous cells, what does that mean to me based on what I see in the clinical history? And then I come up with my differential diagnoses, and then that helps us point towards the right direction. I want to characterize the histologic or the microscopic criteria of eosinophilic esophagitis, and we'll talk about that. It does include some counting that helps us make that diagnosis, and then discuss the clinical findings that help in distinguishing and ultimately reaching the diagnosis of eosinophilic esophagitis versus gastroesophageal reflux, for example. So just briefly, what does a pathologist do? I can tell you most people don't know. Even when I started medical school, I wasn't entirely clear probably what a pathologist did. So a pathologist, a pathology, is the study of disease, and there are two large fields of pathology. One of those is clinical pathology, and that really includes all the laboratories in the hospital. So that includes the chemistry lab, the microbiology lab, the tissue antigen typing lab. All of these labs fall under the realm of clinical pathology. And on the other hand, you have anatomical pathology, and that's where we fall with where we get tissue biopsy specimens, where we get resection specimens. And so here in this picture, you're seeing a, this is a subtotal gastroesophageal gastrectomy, and so just a proximal part of the stomach and the distal part of the esophagus, and we see the Z line there in the center. So to really break it down a little further, within the realm of anatomic pathology, we have surgical pathology and autopsy pathology. I'm a surgical pathologist, and so what do we do? I look at the biopsy, I look at the tissue under the microscope. So on the far left there, you see a nice little characterization of taking a biopsy, and then it goes into, we put it in fixative, so that's most often formalin, of different percentages depending on the type of tissue, it may be alcohol, it depends on what the, you know, what do we want to do with the tissue? So what kind of testing is going to be involved in that? And then that tissue undergoes a process of dehydration and clearing, and then it's embedded in paraffin, and that's, you can see the tissue embedding portion, and then the tissue sectioning. And so this is on a microtome, and that paraffin embedded tissue is sliced typically to four to five microns thick. That's placed on a slide, and then ultimately stained with, here we see a hematoxylin and eosin stain, and that's really the gold standard of pathology. That's that common purple-pink that you might see in pictures and things, in diagrams. So in real life, how does this look? Well here on the far left, we see, so this is what some tissue might look like that would be taken from the esophagus. So a gastroenterologist has gone in, in biopsy, you know, his areas of interest, and we receive these little fragments in jars or containers of formalin, and they're fixed, and they're kind of laying here on a piece of tissue paper. What do we do with that? So that goes in a plastic cassette on that tissue paper, and that's where it's going to go through that processing phase, where it's going to be dehydrated and really fixed and ready for staining and cutting. Then that's where we get to our slide, which is actually the physical part that I look at under the microscope to make diagnoses. And as I mentioned, the hematoxylin and eosin, the H&E staining, is really, is the gold standard. It's what we use for baseline. Here on the far left, we're looking at some squamous cells in the esophagus. And this hematoxylin, these purple arrows, are pointing towards the nuclei in these cells. And as you can see, they stain with a, it's kind of a nice purple color. Sometimes people refer to it as blue as well, kind of a bluish purple, and that's the nuclei of the cells. And that has to do with the more basophilic, or more basic component of the nucleus. So it's staining based on what the molecules are, those components are of the nucleus. So that's where, of course, a lot of DNA is, RNA, whereas eosin is this nice pink color that we see in the cytoplasm, staining more acidic components of the cytoplasm. And so we see this nice little pink color. And these, the variations of the color, the density, that's going to vary based on, you know, the components of that cytoplasm. So for example, in a cell that's, you know, a malignant cell, or a cancer cell, oftentimes we may say they're very hyperchromatic, because the nucleus looks very dark, very deep purple. So we look at all these things and take into account as we make our diagnosis. Some of the key players in eosinophilic disease, specifically like inflammatory disease, are shown here in the image. So the ones that we're talking about here are these folks, these eosinophils that you see by the red arrow. And you can see they have a bilobed nucleus. So you see those two kind of nice, almost kind of like, to me in this picture, they kind of look like two lungs or something, I don't know. Some people say kidney shaped or something, but either way, we see they typically have two lobes. And then they have these granules, these red granules inside the cytoplasm. And so in real life, what do they look like? They look like this. And so you can see that pink, see those pink cells there, let me see if I can annotate, maybe might be more trouble than it's worth. So let's see, right here. So these folks, see they have this very bright red, pink cytoplasm, and that's those red granules that we see. And then we see these two bilobed nuclei. Let's see if I can turn that off now, all right. So what's the normal histology of the esophagus look like? So the esophagus is lined by squamous epithelium, and that's that surface mucosa that we're seeing up there at the top. And that's just these layers of squamous cells piled on top of each other, for the most part, as they mature from the base, and they go superficially. Underneath that, in the submucosa, we see our submucosal glands, we see a lymphoid aggregate here. So it's just some lymphocytes that we see, that's normal. And then underneath that, we see our muscularis propria, and that's these thick muscular bands of smooth muscle. And then in portions of the more upper, more proximal esophagus, there's also a skeletal muscle component that has to do with the voluntary component of swallowing. Just pointing that out again, again, normal histology of the esophagus, a little higher power view here. We see our squamous cells at the top. And then underneath that, we have our lamina propria with our submucosal glands. And as you can see, those squamous cells, we don't see a lot of, we don't see any of those bright pink cells that we saw a minute ago, these eosinophils scattered throughout there, even at this power. So really, we see just a lot of squamous cells. And then there's some scattered lymphocytes in there that you can't really make out at this power, but that's normal, sometimes referred to as squiggle cells. So on initial evaluation, so whenever I get the patient's slide, and I put it under the microscope, what am I looking at? So first off, the epithelium, so that squamous cell layer, that squamous mucosa on the surface, is it atrophic? So is there a lot less of it than I'm expecting to see, or is it hyperplastic? Is there a lot more than I'm expecting to see? Is it perikaryotic? So is that top layer, is it thickened for some reason? What's going on here? The inflammation there, what kind of inflammatory cells are present within that squamous cell lining and in the lamina propria? Do I see more neutrophils, which typically we see in something like candida esophagitis or a yeast infection there in the esophagus. Lymphocytes, so do we see a lot more lymphocytes? We may see that in some inflammatory conditions, in medication-associated injury, things like eosinophils, so obviously, of course, eosinophil esophagitis, where we would see a predominance of eosinophils. But we also see eosinophils in other inflammatory conditions and even in reflux disease as well, or just a mixed inflammatory background. What's going on there? Is there, am I seeing neutrophils, eosinophils, lymphocytes? What could be leading to this mix of inflammation that I'm seeing? The severity. Am I seeing, you know, is it five eosinophils per high-power field? Is it 100? You know, what am I, is it the neutrophils? Are they more in the surface? Are they intermingling within the squamous cell lining? Do I have yeast within the squamous cell mucosa there? You know, so where is everything and what's happening? Is it more at the base of the papillae of the squamous cells, where that might be more towards an inflammatory condition, like we might see in, anyway, just blank there for a second, but that's beside the point. So severity and then the distribution. So where are we seeing that within the mucosa layers or the submucosal layers? Bugs and drugs we talk about. So as I mentioned, like candida, we can see in immunocompromised or immunosuppressed patients. We can also see things like herpes esophagitis, CMV esophagitis. And so we see these infections. We see drugs, different drugs can irritate the mucosal lining there as well. And then, of course, the lamina propria. So is it ulcerated? Is this, you know, like we often see like an ulcer and so, you know, rule out this or that on the biopsy specimen. So is it, are they thinking it's candida because they see something else there? Or is there, you know, could it be a malignancy or something like that that's leading to this ulcer? And then is it very fibrotic in the lamina propria? And that can be one of the consequences of eosinophilic esophagitis. We see this increased fibrosis. And that can, of course, as discussed in the panel, some there lead towards that stricturing and difficulties for the patient. So what is normal? Like, you know, we have eosinophils, they're floating around in our blood, they're in our tissue, but how many is normal? How many is not? How many are too many? So here, this example shows three. And so within the gastrointestinal tract, that whole tube, it's normal to have eosinophils in the tissue, except for in the esophagus. So any eosinophils there in the esophagus are abnormal. So some of the causes of esophageal eosinophilia. So of course, we see reflux there at the top of the list, followed by eosinophilic esophagitis. And you notice, I won't read through the whole list, but you'll notice that a lot of these conditions that we see here are related to inflammatory conditions or autoimmune conditions. So like Crohn's disease here, celiac disease, or again, going back to immunosuppressed patients like those with graft-versus-host disease, systemic hyper eosinophilia. So we see some of these differential diagnoses when we see eosinophils in the esophagus. So baseline, what is eosinophilic esophagitis? So it's a chronic immune-mediated esophageal disease characterized clinically by symptoms related to esophageal dysfunction and histologically by eosinophil-predominant inflammation. So this is a clinical pathologic diagnosis. So that means basically, it's going to require to make the diagnosis of eosinophilic esophagitis. The gastroenterologist or endoscopist, when they're talking to the patient, and the patient's described describing these symptoms, and then they have esophageal dysfunction, and then when they biopsy it, and then I see predominance of eosinophils there in the squamous epithelium, and those things combined can lead towards the diagnosis of eosinophilic esophagitis. But the big takeaways are this is chronic immune-mediated. It's a clinical and histologic combination to make the diagnosis. A bit about the background demographics. So we do see an increasing incidence and prevalence of eosinophilic esophagitis. It's more common in men, about 3 to 1. Typically, in their mid-30s to early 40s, mid-40s, more European and North American descent, greater than Asian, and often more times in a rural area, for example. So more times in a rural area versus urban, and then cold, rural regions. Some of the risk factors for eosinophilic esophagitis include, interestingly, cesarean section, a prematurity, antibiotics exposure early in life, when you think about that inflammatory component, and then there's associations with food allergies, asthma, eczema, allergic rhinitis. Again, all immune-related mediated conditions we often think about with eosinophils. So in asthma, it's a predominance of eosinophils, food allergies, eosinophils, eczema, eosinophils, and then, of course, allergic rhinitis of eosinophils. And then separately, other risk factors of etiology. So is it genetic? Is it environmental? Well, studies have shown with monozygotic twins, dizygotic twins, and siblings that it's more environmental than it is genetic. And that's what this figure here is demonstrating. See the non-significance there of the p-value at monozygotic twins. Environmental antigens. So what is the patient swallowing? What is being exposed to there at the mucosa? So we see here foods in our impaired barrier function, antigens that are being presented to their antigen, that are being handed over to antigen-presenting cells, which are going to release interleukins and helper T, and then that's going to call into place some helper T cells, mast cells, basophils, and then some of these other interleukins, so 4, 13, 5, going to lead towards recruiting more eosinophils. And this can lead towards, you know, this injury over time can lead towards recruiting more fibroblasts, which can increase that fibrosis that we talked about in the lamina propria, and also of our smooth muscle cells can lead towards dysmotility that the patients experience as well. Our diagnostic criteria, just as we talked about, so the clinical, so are there other concomitant atopic conditions, other things that could be causing this sort of allergic type reaction? What are the endoscopic findings? So what do the gastroenterologists see whenever, you know, they put the tube down there? So I always read through the operative note and I look for these, you know, key words, you know, it was narrowing, rings, furrows. The furrows and rings is the big keywords, the buzzwords, if you were to say for, you know, for like a test, for example, or we might, sometimes it's called the, like a feline esophagus, because it has this, or what's called a trachealization. So it kind of looks like the trachea at times, but it says rings and furrows. I also might see edema and then exudates, and then crape paper mucosa. So sometimes we can see a little sloughing of the very superficial layers of that squamous mucosa. And so it's, it's a very thin kind of paper look to it. On the pathology side of that. So when I combine, you know, we combine the findings of the endoscopist with that of the pathologist. So do we see greater than or equal to 15 eosinophils per high power field? Approximately 60 eosinophils per millimeter squared. So high power field for the pathologist, that is a 40x field. So looking through the microscope, our normal objectives, and I think you can see from the picture here, are 10x here. And then I'll use a 40x objective lower and I'll look, so I'll look at, I'll be looking at 400 times power at the side, at the tissue, and then counting eosinophils that I see in my field of vision under the microscope. And then again, this eosinophilic infiltration isolated to the esophagus. So it's going to be within that squamous lining. We're going to see that. So how do I make a diagnosis of eosinophilic esophagitis based on what I'm looking at? So this is a low power view of, again, just squamous, or squamous mucosa in the esophagus. So here we go. Look at this is a little more like more along the point of what we're talking about, eosinophilic esophagitis. So we can see, if you look at the stars here, you'll see, this is the, this is the degranulated red granules that we're seeing within those eosinophils, right? So you think somebody has to make those, right? The eosinophils are there. And then we see our eosinophils. We see some micro abscesses here at the top of the picture under, just, just underneath that superficial epithelium, but scattered throughout, you see little eosinophils. And we see our eosinophilic granules marking that they've degranulated. Again, here's a higher power view of showing more eosinophils within the squamous epithelium. So for me, when I, I put this under my microscope and I look at this and I say, okay, there's intraepithelial eosinophils. So my top line diagnosis would be squamous mucosa with intraepithelial eosinophils. And then I'll give a count. So I'll count this and I'll say, I'm just going to throw a number out right now, 35 eosinophils per high power field. So then I'll go on to describe, you know, what other features do I see that might lend towards a diagnosis of eosinophilic esophagitis versus something else, maybe like estrous esophageal reflux disease or some other infection. So one of the other features I'll look for, and you can see bracketed here, is a basal cell hyperplasia. And basal, just as you might think, is at the base there. And so we see a thickening of the basal cells as we see increased proliferation. We see these nuclei, you can see the nuclei there at the base, a little darker, a little more compact. So that basal cell hyperplasia, one of the features that we see in my senior report. So I may list that in my histologic description in my diagnosis. And then here's another worst case where we're going to see, we see lots of eosinophilic microabscesses at the top there. And we also see eosinophilic debris with some squamous sloughed off lining. Like I mentioned, that crepe paper. So imagine that top, those top bracketed areas here. This is that sloughing off of some squamous mucosa where you can see some of those off of some squamous mucosa with lots of inflammatory debris, including those eosinophils that we see there. So these are all features that we can see that can help lend towards the ultimate diagnosis of eosinophilic esophagitis. This is a higher power view showing these eosinophils here at the, within the, towards the base of the squamous epithelium. And it's pointing towards these intracellular spaces. And so we see, if you look, you know, if you recall from the normal picture we saw, we didn't see these big gaps or spaces in between themselves. You know, they were nicely, nice and compact. They're friendly with each other, nice and close. But here we see these gaps. And so this is an intracellular edema that we see are often, it's called spongiosis. And so this is another feature that we see commonly in eosinophilic esophagitis. And so another thing that I might list in my description of what I'm seeing for the gastroenterologist whenever they're looking in my report so that they can, you know, know how to appropriately treat the patient. And then just for your FYI, here's that normal. So you compare that normal squamous on the top right there in that inset to this eosinophilic esophagitis that we're seeing on the left. And sometimes things just get, you know, kind of out of control. And this is what we see here, this giant layer, almost abscess of eosinophils in debris. And this is what this would look like in the endoscopy, these large abscesses. And then lastly, we mentioned the lamina propria fibrosis, and that's what's being highlighted here in these brackets. So we're seeing these, if you see these like thick pink bands of smooth in the lamina propria here running through. So that's that increased fibrosis that we see that leads towards that patient experience of the stricturing and discomfort and difficulty swallowing. So easy, right? Just slap it under the microscope and look for a few things, huh? All right, let's go back and look at a few examples here. So what are we seeing here? In the center picture, we see a low power and then on the top left there, more of a higher power view. So that you can imagine that might be something like I would see in a microscope when I'm gonna go to make my eosinophil count. How many do I see per high power field? And then it can be a very patchy disease. So if we look in the center there, so I have two pieces of tissue or two pieces of squamous epithelium from the esophagus. One of them on the top left here, I see increased eosinophils. And on the far right here, I see a few eosinophils, which of course are not supposed to be there, but I certainly don't see more than 15 per high power field. So it can be patchy. And that's why the endoscopist usually will, there's a number that we'll talk about later that can really increase the sensitivity to make the diagnosis of eosinophilic esophagitis. So the numbers game, this can be a bane of many pathologists, it's counting things. But again, so a peak greater than 15 eosinophils per high power field. So some of the advantages of this, of course, the density is pretty objective and quantifiable, and we can have a high degree of inter-observer agreement. So for example, when I'm teaching my trainees, I'll have them count and then I'll count and we'll compare notes, and then we'll discuss our approach so that we can be on the same page. But oftentimes of many things that pathologists do, this counting in the field is gonna be pretty objective there. There are some limitations to it, of course. Does that actually correlate with symptoms? Yeah, I see eosinophils, but is the patient experiencing symptoms of that? The heterogeneity and methods of counting. So some people may use a microscope that has a cytometer built into it so they can count from that. Some may kind of split their field of vision up into quarters or halves or something like that and count and multiply if things look even, or it may just count straight through the whole field. Some people may say, some pathologists may sign out the case and they'll say there's greater than 15 per high power field. Some may say there's greater than 60, or some may say greater than 100. That's also some kind of pathology-centric, what they say. And it's also, it's a nice discussion for the gastroenterologist to have with the pathologist too, as far as what can I say that's gonna help you and help guide you towards treating the patient the best that can be. So personally, I say when it's greater than 100, I just say it's greater than 100, but I will provide a number up to that point if it's less than that. The threshold to define response is not really established. So how many eosinophils, there's too many there. There can be a incongruence between symptoms and what we're finding histologically. Tissue sampling variability. So how many biopsy pinches are they taking? Where are they taking them from? So of course that's very endoscopist related. And then incomplete measure of disease activity. So again, we may not be able to tell how severe it is just based on the eosinophils that we see. Oftentimes, a biopsy may not contain any laminopropia. So I can't tell you if there's increased fibrosis or not. So has this been ongoing for a longer time or not? Is there more chronic injury seen here? A lot of times we just have some squamous epithelium, just that surface layer there. And so I can just tell you about what I'm seeing in that point. I'm running out of time. All right. So some of the causes of esophageal eosinophilia. This is we talked about earlier. Reflux, one of the big ones. And then let's take a closer look at these two. Eosinophilic gastritis versus reflux. Often younger patient. Both more typically male. The presentation I talked about earlier. So that solid food impaction, dysphagia. Versus on reflux, patient more often experience heartburn and regurgitation. And then again, the endoscopic findings. Those rings or furrows. Might see some exudates. And then on the other side, most patients with reflux, they may have some erosive esophagitis. So they may have a canulsa or something there at the base or near the junction. May have a hiatal hernia. So these are all things I look for too in the endoscopy report when I'm trying to do, determine what's going on with the patient. And then do they have any embarrassed mucosal changes at the junction as well? Many EOE patients, I'm sure you all have talked about already, experience heartburn. And then symptoms of EOE and reflux are similar in children. So difficulty, failure to thrive, vomiting or just food aversion. So reflux. Again, we may see a mix of inflammatory cells in reflux, but oftentimes I do see some eosinophils. So I may get a biopsy from maybe the lower esophagus or the esophageal junction. And I will see a few eosinophils, but typically in reflux, I won't see more than that 15 par high power field that we see in eosinophilic disease. And there may be some neutrophils. There may be some lymphocytes. There may be a little more going on there as that tissue is reacting to that acid that's being refluxed in the esophagus that's escaping back up there. As we talked about that basal cell hyperplasia, we can also see that in reflux esophagitis because it's a reactive process that's reacting to the acidity. Elongation of the limb and appropriate papillae. And I'll show you a picture of that. Some vascular dilation. And then that spongiosis, that edema that we discussed. So you can see there's a lot of overlap in some of these reactive changes that we can see. So here's an example. Like this was a patient that had more of a reflux type of esophagitis. And we see some vascular papillae elongation. And that's that. You see those kind of cutting up into, oops, I was trying to delete that, but we see these vascular papillae like rising up into the squamous epithelium there. You see a little spongiosis. We see some eosinophils. But again, we don't see that density that we see, that greater than 15 per eye power field that we saw in eosinophilic disease. Again, same thing here. We see these kind of vacuolated spaces sometimes. Some people call them balloon cells. Again, more reflux esophagitis, but again, a lot of eosinophils in this situation. So again, there is that overlap. So that's why we're, you know, it's combining with the clinical side of things. What's the endoscopist seeing? What's the patient experiencing? So if I were to just give a count and the number, you know, not any other details, that can of course help the endoscopist, but that's not going to ultimately guide or say whether or not, you know, I'm not saying it's reflux versus eosinophilic esophagitis. Again, here's another example of reflux disease. We see that elongation of the vascular papillae and some of that basal cell hyperplasia. We do see some scattered eosinophils in there. And then one more time to like compare it. Again, there's not a clear distinction. It can be overlap. Certainly patients can experience both things, you know, but on the eosinophilic esophagitis here, we see that again, that basal cell hyperplasia, diffuse involvement of the epithelium. So we often get, you know, evaluate for eosinophilic esophagitis, check my time, eosinophilic esophagitis, and let's say it'll be a proximal biopsy. So I'm more super, or more towards the, more towards the mouth and then a distal biopsy. So more towards the stomach and we'll evaluate. And oftentimes in eosinophilic esophagitis, we'll see increased, the eosinophils will be more proximal. So higher up in the esophagus than they are in the, than we will see eosinophils in reflux disease. In EOE, those degranulated eosinophils, very striking micro abscesses that we saw in some of the pictures, the density, moderate to marked, and then that laminate appropriate fibrosis. So they're all differences that we see versus EOE from reflux disease. So again, it takes correlation with the clinical findings, the clinical history and chart review, has this patient had EOE before and is it getting better or worse? Where is the eosinophilic disease? So where did the biopsies come from and where am I seeing those, all this striking eosinophils? Here's an endoscopy, what they mentioned about the furrowing, those rings, as you can see, and then that edema and exudates, that bottom right picture, so a very edematous mucosa with some like inflammatory exudates on the surface, that kind of yellowish tint you see there. Here's an ultrasound on the left there of the normal esophagus versus eosinophilic esophagitis. You can imagine all that edema that we saw, those reactive changes in how, so you can see the differences there between that normal and that eosinophilic esophagitis case. Again, here's a head-to-head comparison, EOE versus reflux. We see a lot more eosinophils, a lot higher density, just as we talked about there on the left versus the right. And lastly, some just diagnostic tips and pearls. So 15 per high power field is a criteria, but it's not definitive, so it takes that clinical and the histologic findings. Endoscopic findings in the clinical history, especially treatment-related, can be obtained. You know, it can be a patchy disease, so if you take one biopsy, we have about a 55% diagnostic sensitivity, so we can miss a lot. We can have a lot of false negatives, whereas six to nine biopsies, we've been shown to have 100% diagnostic sensitivity. I can't tell you how many times I get a slide of the proximal esophagus, and it's got, say, five pieces of tissue on there, and only one of those pieces or two of those pieces have a ton of eosinophils in it, and the others may have just a few or none, so it can be very patchy. And then, of course, correlation with prior examples from the patient's pathology report. Is this getting better? Is this getting worse? And then those are things that, of course, your gastroenterologist will put together with what they're finding now with the patient's experience. With that, we'll finish up. Thank you, and I'd be happy to answer any questions if we have time. The question was, there's different labs that sort of comment on eosinophil count and some report it as low, medium, or high. Can you explain that a little bit to us and why the reporting might be variable or what that's involved? Sure. Yeah, you know, that may come down to the pathologists and their training, you know, where they were trained and how they were taught as far as low, medium, or high. I certainly favor and, you know, given the diagnostic criteria of greater than 15, you know, a number is much more accurate. And because, again, you know, just as they pointed out, what does that mean to me versus to you? Low, medium, or high? Is high greater than 15 so that, you know, is diagnostic or is high 10 or medium 10? So that's one of those areas that, you know, it's not exact and, frankly, like a good discussion between the endoscopist and the pathologist so that everybody knows what you mean. It's one of those areas where there are situations when that's necessary for the best, you know, patient care. So is this patient, how many is low, two, but, you know, as I said, there shouldn't be any. So one, is that low, is that high? So it's a discussion that I would say the gastroenterologist should have with the pathologist so everybody can be on the same page. Great. Thank you. Other questions? Yeah. Here. Hello. I'm just curious, for the times that you have the opportunity to see a repeat biopsy on a patient who was not on medication and then was put on either topical corticosteroid or PPI, I'm curious what your observations are in terms of, how can I ask this? Like, do you see a difference in how fast the acinophils count are coming down? Like, what's your observations with treatment over time with the repeat biopsies? You know, that's, you know, I do see as the patient, you know, when I get a slide and I'll scan it, I'll see, oh, you know, they had an endoscopy six months ago and there was a ton of, you know, eosinophils and now I see, you know, a few, or I see, you know, much, much decrease. So I only see 10 per hypothalamic field and then I can look in the chart and see, oh, they were placed on, you know, this medication or something like that afterwards. So I, you know, I see the response, but as far as which medication, that would, I would point that one towards my gastroenterology colleagues, as far as, you know, their responses in the patient response to therapy with what I see. But, but as far as what I see after treatment, I see a, basically a big decrease in that the eosinophil count I'll see, you know, over time, like less and less of that basal cell hyperplasia. I won't see that spongiosis, that edematous squamous epithelium that we saw. So I see those things tend to resolve. Is this when you use that famous tagline, clinical correlation requested? The favorite, huh? Yeah, but that is, you know, and that's, I think one of the points from this talk is, you know, clinical correlation, whether that's, you know, I, I do that and I am urging you to do that too, because, you know, again, this is what, this is the clinical pathologic diagnosis. So it takes, it takes both of our findings to, to give the patient this diagnosis. So it's this, you know, that's also one of those veins of some pathologists or not, but because we're all should clinical correlate, we're all physicians and trying to take care of the patients. But yeah, so we always just want to make sure you are interpreting the things that we're saying in our report underneath the umbrella of what you're also seeing, you know, on your exam of the patient and the patient's telling you. Great. We have a question back here. Hopefully I'm not going to blow away the microphone. You mentioned that when, when you're doing the pathology, a lot of times with GERD, you'll see a lot of eosinophils as well. So when you report that back, are, are you just listing the eosinophil count or are you making comments on whether you think it's GERD or EOE? Do you typically go with one diagnosis or is it a dual diagnosis back to the, the gastro? And thank you for sharing. Oh, thank you. So, you know, I'll give the count and then I'll describe other things that I might see. So if I see, you know, oftentimes with GERD, the biopsy will be from the more distal or, or even from the gastroesophageal junction. And so I may see more like plasma cells. I may see more lymphocytes. There could be some ulcerations. So there could be other components that I see more often in GERD than I see in eosinophilic esophagitis. So I'm trying to, you know, like paint a picture of histology of the histology or description of that, of what I'm seeing for the gastroenterologist to say, Oh, like these are the features he's seeing. And so now like, you know, that fits more with EOE, which is what I'm thinking. And then versus the patient's experiencing this, and this is more towards the junction more approximately, there's no eosinophils. So this fits more with eosinophilic esophagitis rather than, or, or GERD rather than EOE. So I try to paint a picture there and if it's, you know, the differentials kind of called into question, then I may give a comment that I favor one or the other. And then of course, you know, we can always, always urge our endoscopy colleagues to, you know, just give us a call if there's any question about anything. The question is, the follow-up is, are most endoscopists listing for you where the tissue samples are coming from, or how do you know where the sample is from? Sure. Yeah. Yeah. And they, they do, they will list that. And so we'll receive the, the typical scenario for a patient they're concerned about EOE is I'll get, they'll send two jars. The first one will say proximal esophagus, and the second one will say distal esophagus. And so they'll biopsy, you know, they'll take those six to nine pinches from those two areas. And then I know, so, you know, my part one of my case is from the proximal and part two is distal. And so then do I see a ton of eosinophil as proximal or a ton versus distal? You know, do I see just a few distal and nothing proximal? So that helps guide also whether, you know, it's more GERD related or EOE related. So that's, you know, them separating the specimens or those biopsy specimens, just like, you know, anywhere else in the body, like if they were to sample the colon and take from the right versus the left and so on. Great. Thank you. Good morning. Excuse me. So we're noticing early on that some of the insurance companies are requiring folks during the recertification process at either four months or six months to take another biopsy. And the biopsy has to show an eosinophil count below a certain threshold in order to be recertified, right, for the next couple of years. So if you have a lab that is categorizing as low, medium, or high, is there something that the office or provider can put on the lab work that requests an eosinophil count versus a category to support the recertification process? Yeah, that's great. And I'll give you an example here. So a couple of our endoscopists will put in that same area, we'll say on the requisition where it says proximal esophagus or distal esophagus, it'll say, you know, oftentimes they'll put a comment. It says, you know, please provide peak eosinophil count, you know. So we see that and then, you know, and of course, you know, we ought to be concerned about EOE. So I can see that and I can provide that account, you know, that account there. So it can be a matter of just leaving a little note there to say, you know, ask for that because, you know, that's going to help you make a decision or help the endoscopist make a decision on the next treatment steps for the patient. Or you know, it can just be the physician, you know, just giving the pathologist a call and say, hey, some of our insurance companies, they need a number and can you please provide that, you know, in your reporting so that we can, you know, the patients can continue to get treatment. Excellent. Excellent. I think we have time for one more question, anybody? Just super quick, who's actually, who actually does the dehydrating of the samples? Is that you or somebody else? Lab technicians. Yeah. Okay, perfect. Within the pathology field in the realm, the lab is a myriad of different technologists and histotechnologists. We rely on a lot of ancillary staff, just like, you know, the clinicians out there relying on, you know, your nurse practitioners and nurses and everyone else that takes care of the patients. And because that was really fast, we can go with one more. I thought I saw another hand. Is there one? Yeah. Okay, cool. I'm going to try to mosey. How quick does the tissue samples have to be delivered to you? So often it's next day, they're signed out. So the endoscopist will take the biopsy, say, you know, today, those samples will get taken to the gross lab and the pathology and where they're processed, you see, they'll put in that cassette, that plastic cassette as those fragments of fixed tissue. And then that'll go, that'll later in the evening, get put in the processor in the morning early, there'll be a histotech. Usually it's like two, three in the morning, and they'll start cutting those slides that have come out of the processor and then staining them so that, you know, me in the morning when I get my slides, you know, say eight o'clock, I'll get those biopsies from yesterday and I'll look at them and then sign them out hopefully that day, the next day. But if they're placed in formalin, you know, some days it may be, you know, you may get a whole bunch, the whole day's worth at one time, you know, so that preserves it well. Excellent. Thank you so much, Adam. Really appreciate your help. Thank you for the fantastic questions. Again, like I said yesterday, you guys are awesome.

eosinophilic esophagitis

pathologist

histological criteria

diagnosis

differential diagnosis

intraepithelial eosinophils

clinical correlation

endoscopic findings