All right. I think we're going to get started and also give people some time to come in. Good evening, everyone. Welcome to the Florida Society of Pathologists' evening CME lectures via Zoom. Today, our speaker is Dr. Gregory Lowers from Moffitt Cancer Center. The topic is Diagnosing Various Esophagus Twists and Turns and the Lessons Learned. Before we start the lecture, we're going to have just a few housekeeping messages. First, all the audience are muted, but you have the opportunity to enter your questions through chat. I already saw a couple of chats coming in. Everybody is saying hi and greeting each other. So very well, this is how you submit questions. And the lecture, we will start the introduction, and then we're going to play the pre-recorded lecture from Dr. Lowers. And when the video is over, we're going to turn on the live discussion. And this time, we're going to discuss all the questions submitted by the authors. So as you can see, this lecture is recorded. The recorded lecture will be placed on the State Society website. So if you want to review it, and you can, which is an on-demand lecture. But because you're registered to this lecture, you will have the opportunity to claim credit by June 13. And you probably already received a special email as attendees and with the instruction of how to claim CME. So without further ado, let me introduce my colleague, Dr. Gregory Lowers, to give this lecture. And I am one of the officers of FSP. I'm very excited that my home institution, Moffitt Cancer Center, joined FSP as a group member so we can support each other. And Dr. Lowers is the senior member in the anatomic pathology department, also the director of the GI pathology unit. He's also the professor in the department of oncological sciences and the pathology and the cell biology at the University of South Florida. Dr. Lowers received his MD from the University of Paris, France. He completed a surgical pathology residency at the Lenox Hill Hospital in New York, New York, and a fellowship in oncological pathology at Memorial Sloan Kettering Cancer Center, where he also served as chief fellow. Following his fellowship, Dr. Lowers was in the division of anatomic pathology of the department of pathology at the University of Florida in Gainesville. From 2000 to 2016, Dr. Lowers was in the department of pathology at the Massachusetts General Hospital in Boston, where he rised to the rank of professor and also later on became the vice chair of the department. Dr. Lowers has published over 400 peer-reviewed articles, editorial reviews, and book chapters, has co-authored several textbooks, including the fifth edition of Morsen and Dawson's GI pathology book. Dr. Lowers serves on the editorial boards of several journals. He is the deputy editor-in-chief of the archives of pathology and the laboratory medicine. He contributed to the WHO classifications of tumors of the digestive system for 2010 and the 2019 editions. Dr. Lowers' areas of clinical interest include the luminal malignancies of the gut, particularly esophageal and gastric adenoma, and the hepatocellular carcinoma. So as you can see, Dr. Lowers brings us a lot of expertise and the excellent record of teaching and research and the publication. So without further ado, we're going to ask Dr. Lowers a couple of questions later, but right now we're going to get into his lecture. So Amber, please take it away. Well, good evening. My name is Greg Lowers, and I wanted to thank the Florida Society of Pathologists for their invitation. I hope that this Zoom lecture will go through. That's the first time I'm trying this, and it hasn't been working too well. So hopefully that will be the last one and the good one. So what I'm supposed to talk about today is diagnosing Barrett's esophagus twists and turns and lesson learned. And I'm going to limit my discussion to actually some cases. You won't see many tables and articles. It's mostly based on experience, or at least my experience. And we're going to talk about dysplasia, basal gland atypia, the difference between high-grade dysplasia and intramucosal cancer, and the issues related to endoscopic resection. So obviously, every time we get a biopsy in the setting of a patient with Barrett's esophagus, we are always looking for whether there is dysplasia or not, and if there is neoplasia, is this low-grade, high-grade, or intramucosal cancer. So you see on that low-power picture, you have a sharp demarcation between the non-dysplastic and the dysplastic epithelium. Here at higher magnification, you see the sharp transition between the normal benign Barrett's and the nuclear hyperchromasia and overlapping. Here you see the sequence from low-grade to high-grade, where the nuclear features are worse, with rounding of the nuclei, stratification, maybe even glands within gland here, and obviously intramucosal carcinoma there. There has been multiple series that look at the criteria, whether they are cytologic or architectural, to make a diagnosis of low-grade and high-grade dysplasia. However, I just want to emphasize to the lower half of the picture, we need to recognize and remember that dysplasia is a spectrum of changes. It's not always low, always high, as you've seen, and I'm sure you see low to high, etc. So it may be difficult to always put one single grade, number one. The other thing that we need to recognize is that the assessment of dysplasia is not perfect, has never been perfect, and will never be perfect. We are looking at biologic features and, you know, it's difficult to put a single yardstick and say this is low-grade, this is high-grade, or not, number one. The second thing is that all the studies looking at dysplasias are not real-life studies. They are, everybody look at one slide, one field, make a diagnosis. Is this not the way you make a diagnosis? When you have a diagnosis of dysplasia, you look at it, you look at the biopsy before, after, levels, you talk to your colleague. It's not what's happening in any of the studies. And finally, there are impediments to accurate grading of dysplasia. Technical quality of the slides on that day, there is clearly overlapping of the same feature that we use to make a diagnosis of dysplasia versus reactive changes, and we don't always know, and there is no good clue to this. What are the most important cytologic features, architectural features? How do you make the synthesis of those features? And then finally, there is histologic diversity of dysplasia, intestinal dysplasia versus fovella or type 2 dysplasia that we will not discuss today. So, let's look at some examples. Reactive changes of dysplasia. So, clearly there is glandular crowding, some disarray. If you got higher magnification, there is nuclear hyperchromasia, some stratification, mitosis, overlapping. Is this dysplasia or not? So, there is scattered intraepithelial neutrophils as well as lymphocytes. There is stromal inflammation, as you can see here, maturation, granulation tissue. The nuclear and cellular features are quite uniform, right, from one aspect to the other. Finally, here, you can see the surface maturation. Clearly, the surface here is not equivalent to what you see here, and there is also limited mitosis, there is overall maintained nuclear polarity. This is reactive changes mimicking dysplasia. Let's look at another example. This distinct nuclear hyperchromasia. If you got higher magnification, round nuclei, clearing of chromatin, prominent nucleoli. However, the key features here is the marked neutrophilic infiltrate. When you have so much inflammation, back off. Unless it's really, really ugly, those changes need to be interpreted as at most indefinite for dysplasia or maybe reactive depending on other features on the biopsy. But significant acute inflammation should really make you pause when you have a case like this one. Let's look at this other example. There is glandular crowding, there is even gland-to-gland here, there is some nuclear hyperchromasia that goes up toward the surface, reactive changes or dysplasia. You see in that example here, maybe a few neutrophils. But let's spend more attention this time to the stroma where there is clearly granulation tissue, maturing granulation tissue. This is, in my opinion, evidence that this Barrett's esophagus has been eroded, there has been erosion, there has been re-epithelization, there is maturation of a granulation tissue, and the epithelium is just a reactive epithelium. Finally, another example, you can see marked architectural disarray, back-to-back CREBI forming, nuclear hyperchromasia, overlapping of some of the nuclei. Is this reactive or dysplasia? In my opinion, you have only reactive changes, and based on one, the maturing granulation tissue, again, you see there's a lot of inflammation, there is ectatic capillary vessel, this is just reactive granulation tissue, maturing granulation tissue, and there is surface maturation as well. So, do I always know? No. Is there cases where I use the term indefinite for dysplasia? Certainly. And when I make this diagnosis, it's because I could not answer positively to any of those two answers, at least my answer was negative. Is the epithelium unequivocally reactive, or is the epithelium unequivocally neoplastic? If I respond no, then this is indefinite for dysplasia. And your patient is best served, your endoscopist is best served, the patient should be then vigorously treated by a proton pump inhibitor and re-biopsy. Let's look at another set of cases. So, this one is obviously squamocomular junction, there is columnar epithelium here, kind of hyperchromasia, the surface, maybe a little bit of maturation, but certainly glandular disarray. And our colleague, who sent me the case, was worried about the basal glandular elements. Clearly hyperchromasia, clearing of the chromatin here, you see a nucleoli, some stratification, some overlapping, some sharp transition, you see a small little gland here, mitosis right there. Is this dysplastic or not? Let's look at this. There is actually, eventually, there is glandular irregularity, a little bit of maturation. So, I think that we are dealing with, despite the limited maturation, with metaplastic atypia and regenerative changes. So, what is regenerative metaplastic atypia? Metaplastic atypia is a term which I believe has been coined quite some years ago now by Dr. Roger Haggit for all those atypical nuclear changes that you see in the proliferative zone of metaplastic epithelium, maybe in barrett's esophagus or in the stomach. And you can see that there is maturation going both ways, toward the base of the mucosa, toward the little glands, and toward the surface with a normal surface, non-dysplastic barrett's epithelium. If we look at higher magnifications, here we are again, very atypical nuclear features, there is clearing, there is overlapping, you can see nucleoli, you can see increased mitosis, but you have maturation both ways, toward the base and toward the surface. This is different from basal crypt atypia or basal crypt dysplasia, that is the lesion that you want to differentiate. So basal crypt atypia or dysplasia, you can see that those atypical nuclei, and we'll look at them at higher magnification very soon, occupy the lower half of the gland, there is no normal little glands like here, it occupies all the entire length of the glands. If you go at higher magnification, very atypical nuclei, clearing of chromatin, irregular nuclear contour, prominent nucleoli, marked mitotic activity, nuclear necrosis, apoptosis, this is a neoplastic epithelium, and the surface again is normal. However, a couple of questions remains when it comes to basal crypt dysplasia, is what is the progression to cancer, and actually when you see a high-grade dysplasia, traditional high-grade dysplasia, and actually if you go back to one of the original studies, it's important to consider it in about 80 plus, 80% of the cases, those patients with basal crypt dysplasia, they had already dysplasia in another biopsy focus, or they are going to be very soon diagnosed with this. It's more like a marker of a current high-grade dysplasia. Finally, the other point I wanted to make is that if you do deeper levels on some of your basal crypt dysplasia, like in this example, as you can see here, eventually what you're going to see is some degree of maturation, but this plastic epithelium going toward the surface. So it seems that in some cases basal crypt dysplasia is a progression, dysplasia in progress, you know, toward a more traditional dysplasia that will involve the entire length of the epithelium. Let's look at this other case. So this is obviously another biopsy for patients with barrett's esophagus, and it's very worrisome, nuclear hyperchromasia, mucin depletion, some CREBI forming. So let's look at higher magnification. Two hyperview that I took for you, one on the right, kind of tubular glands, and you can see here again, the same features that we associate with high-grade dysplasia. Nuclear irregularity, clearing of chromatin, prominent nucleoli, mitotic activity, overlapping. Okay. And on the other field, right there, you can see CREBI forming with neutrophilic infiltrate, et cetera. So what is the diagnosis? Let's go back to the original slide. And I wanted to answer this question. So what is the diagnosis? Let's go back to the original slide. And I wanted to emphasize there is this area right here. And if you look at this at high power, this is the way it looks. You have clearly the CREBI forming again, but this time with microabscesses. Here you have a longitudinal view again, but maybe some degree of maturation. But what's very important here, in my opinion, again, is the presence of those numerous ectatic capillaries, which are evidence, in my opinion, of again, reparative, regenerative granulation tissue. So, is this plastic or is this reactive? Could this be reactive at EPA? So, we've done some levels, doesn't help. Should we do special stains? So, I am not to talk today about p53. There's been multiple studies that shows limited value of p53, but there's still some people who go on and lectures and say that you should not use p53. I'm not going to go there. What I'm going to advertise is another stain that I use quite frequently, and that stain is very simple. You have it in your lab. It's Ka67. So, this is the same section with Ka67, and you see this marked proliferative activity in the base, in the glandular, and then in those areas that look like pre-deforming. You see the proliferation going up, but notice that the proliferation stops right there, stops here. The surface is essentially not proliferative. Those are the features of a proliferation which is in check, which is under control. The cellular control for proliferation are maintained. This is marked proliferation. This is not dysplasia, and I can tell you in many difficult cases, I use Ka67 when I'm not really sure to help me eventually decide one or the other. This is another example that was sent to me by one of our colleagues for a consultation recently, and you can see obviously Barrett's esophagus, and this is the area of concern that he highlighted for me. So, why is this maybe worrisome? Well, there is clearly normal Barrett's here and there, and then you see this area a little bit, maybe mucine depletia, maybe stratification, although I must tell you that was not, I was not much concerned, but this clearly sharp transition. So, if I disagree with someone or a case is sent to me for consultation, at least I like to give my opinion based on some evidence and not just this is the way it is or this is the way it is not. And I thought that here again, in this case, Ka67 was helpful. You can see clearly this increased proliferation. Clearly, this epithelium is a little bit more proliferative than normal. It goes, normal proliferative epithelium should stop right there. You can see here it goes a little bit higher up toward the fovellar region, but again, you can see that in this example, there is no nuclear positivity on the surface, and therefore, this is again evidence of reactive Barrett's epithelium and not dysplasia. Let's look at now some example of dysplasia, low-grade, high-grade, and intramucosal cancer. So, this is, I hope you agree with me, a typical case of low-grade dysplasia. The architecture is preserved, the nuclear polarity is preserved as well, the surface is affected, so no problem there. We all agree, Kappa of 1. This is another example, this time that I will diagnose as high-grade dysplasia. Clearly, there is nuclear, the architecture, sorry, is preserved this time, but there is, the nuclear are rounder, there is more stratification than in the previous example, this clearing of chromatin, kind of boulder-like nuclei, this is high-grade dysplasia, and you can see the same stratification on the surface. This is another example of high-grade dysplasia, and you see here the features will be different than in the previous case. There is clearly cytological atypia, but on top of that, there is architectural dysplasia, some architectural dysplasia. So, let's look at some of those features at higher magnifications. Number one, there is stratification, but it's variable, so it's not the worst when it comes to this, but you start to see irregular nuclear contour, start to have clearing, maybe here and there. Okay, it's not the worst, but then on the other side of a biopsy, other section of a biopsy, you start to see much more worrisome, at least in my opinion, features of a high-grade dysplasia, roundness, you know, boulder-like nuclei, clearing chromatin, clearing prominent nuclei, here again, almost glands within glands, all the features of between anisocliosis, nuclear variability of high-grade dysplasia. Let's look at this biopsy. So, it's eroded, it's eroded and inflamed, and we have been taught that if it's either one, well, maybe you should back off, and we have to be cautious. Clearly, here, I see some small cuboidal epithelium, clearly there is something, but I would not commit on this with some fibrin on top. But here, what's going on here? You see here, under the surface epithelium, there is those three small glands, abortive glandular structures, with preserved irregular nuclei, with prominent nuclei, this is at least high-grade dysplasia. And the erosion, the inflammation, nothing else cannot explain the cytonuclear ATPase. So, you have already advanced neoplastic process, it's not low-grade, it can be at the very least high-grade dysplasia, but the way I signed it, I did not see evidence strong enough for me to make a diagnosis of intramucosal cancer. Intramucosal adenocarcinoma is clearly the next step, and we know that since the advance of endoscopic mucosal resection was a new endoscopic technique, the differentiating between intramucosal adenocarcinoma and high-grade dysplasia is less important, and that's true. However, I will re-emphasize that the rate of lymph node metastasis for intramucosal adenocarcinoma is between 2.6 and 5%, meaning that depending on our diagnosis, if there are other features, including, for example, enlarged lymph node over one centimeter on EUS, the physicians may make a therapeutic decision, i.e. surgery versus endoscopic resection, based on our diagnosis. So, although in some circumstances, it's not as important in others as it might be. What are the features to make a diagnosis of intramucosal adenocarcinoma? Absence of surface maturation, various degree of architectural alteration, including creviforming, back-to-back glands, micro glands, withering, abortive glands, and no well-established dysplasia, and I will explain this. Cytologic features of high-grade, irregular nuclear contour, frequent nucleoli, variable inflammation. A couple of examples. So, this one, obviously, we will all agree, intramucosal cancer, there's creviforming, irregular nuclear contour, small, withering, abortive glands here. Let's not waste much more time. You all agree with me. This one is another example of intramucosal cancer, where this time the lesion is composed mostly of a small, abortive, withering, glandular structures, and this early desmoplastic process. There is no fibroblastic desmoplasia. What you have instead is this mixoid transformation of laminar prokaryote, which is evidence of early desmoplastic reaction to the tumor, which is frequently accompanied by eosinophils as well. What about this case? High-grade dysplasia or intramucosal cancer? Clearly, we are above the muscularies, so this is at most intramucosal cancer, and I can tell you my opinion was intramucosal cancer, and the criteria that I use here to make my diagnosis are, one, the presence of some abortive glands here again, back-to-back, okay, and again, and those back-to-back and what we call hand-in-hand, anastomosing glandular structures, which are beyond, I think, what we should expect in high-grade dysplasia. So, based on this, I make a diagnosis of intramucosal cancer. I wanted to advertise one paper that came 12 years ago now, nice paper from University of Michigan, where basically they look at their esophagectomy with the diagnosis of cancer, and they went back on the original biopsies and see the feature that may have been missing, or they may have missed to make a diagnosis of cancer, and what they recognize is the features which are more predictive on biopsy of cancer in resections, and they are cribiform solid growth, dilated glands with necrotic debris, ulcerated high-grade dysplasia, neutrophils in dysplasia, and invasion, and based on whether none of those features, one, two, three, or four of those features were present, what they have a chance to make to properly make a diagnosis before surgery of invasive adenocarcinoma, and here, what they, a couple of the other features that they recognize, I told you about, sorry, cribiforming and solid growth, okay, so cribiform in that example, and again, the dilated tubules with necrotic debris, all features really a good indicator of much of a adenocarcinoma on resection specimen. In the last few minutes of my talk, I will discuss now issues related to endoscopic mucosal resection, which is now this new endoscopic technique that our clinical colleagues are using to remove not only dysplasia, but also polyp in the stomach, in the esophagus, etc. So, just a couple of technical information. Once the endoscopist identifies the lesion, they will inject xylokine and saline under the lesion, forming what they call a belay. If it does not form a belay, that means that the lesion is deeply invasive, and they may decide not to go for anything, and to pass the patient to surgery, but if it does, like this, that means that the lesion is superficial, then they may use different techniques, but they may use a cap, you can see this translucent cap here on that picture, and then they will go over that nodule that they will aspirate, before that they will have frequently, depending on the techniques, they frequently use an elastic lasso, kind of a ligature over the lesion, you can see the lesion which has this more reddish appearance there, and then they will resect it. The problem with endoscopic mucosal resection is that depending on the size of the lesion, the plane of section is limited and the size of it is limited. There's a new technique that the endoscopists have developed, which is called ESM, endoscopic submucosal dissection, but it's used only in some, not in all centers, even academic centers in the US, and therefore I won't talk about this. So, endoscopic resection is the technique now that most endoscopists in general hospitals and endoscopic practice can perform, and depending on the size, again, they can go multiple times, and if they go multiple times, that means you're going to have fragmented material, you're going to have to fix that, but obviously with fragmented material, what you're going to have is inappropriate evaluation of lateral margins. You can clearly say the deep margin is involved, but lateral margin is impossible. So anyway, you get the specimen, you pin it down, you fix it over 24 hours, and then you try to, as much as possible, get one to two millimeter fixed section that you place on the side. So, this is the way to look, don't put too many sections in one cassette, it's better to have three, four, and to have two cassettes, and this is a good endoscopic mucosal resection. Those obviously are bad ones, fragmented specimens, it's not going to help you to make good diagnostic evaluation, because there is a lot of information that the endoscopist wants from you. He wants to have indication of a margin, not only the deep margin, but the lateral margin. He wants to know also the grade of a lesion, he wants to know whether or not there is lymphovascular invasion, if possible, and he wants to have an indication of a stage, how deep the lesion evolves. Obviously, this is one of the best EMR I had, the orientation is perfect, you got everything. You and I know it's not always the case, but we have to deal with this. Another complicating factor, as you know, is that there is fibromuscular anomaly in Barrett's esophagus. As you all know, the squamous epithelium has obviously a surface, there is a lamina propria, and the muscular mycosis. Once you have a metaplastic columnar epithelium, what you're going to have is a duplication of a muscular mycosis, with a neo-muscular mycosis, which is going to be right under the epithelium, then you're going to have the neo-submycosis here, and then you're going to have a true muscular mycosis. So, this muscular mycosis is going to correspond to this, okay, and eventually you're going to have a submycosis right here. So, you need to remember this. However, this is again a beautiful image. In some cases, like this one, and I obviously used actin as an immunohistochemical stain, you can see that it's not so well-oriented. It's difficult sometimes to know exactly where we are, and there have been several studies, one included at the most recent USCAP, which we all attended virtually, of course, where they demonstrated that the fair amount of inter-observer variability in the staging of a lesion was actually in relation to the architectural features of the muscularis, where exactly to measure and to gauge the depth of invasion. There is other features that we need to evaluate, or just be aware. So, this is another case of a dysplastic epithelium, you can see right there, and here is this invasion. Now, like in colonic adenomas, you can have misplaced epithelium, pseudo-invasion, and you can see this dysplastic epithelium under the duplicated muscularis mycosae, still surrounded by normal lamina propria, and you can see the same morphologic feature. So, be aware of that. Then I'll show you a couple of other problematic areas that we need to be aware. So, this is a case that was sent to me in consultation, where our colleague made a diagnosis of deep positive margin. There is clearly invasion there, and you can see the invasion coming right there to the ink, and I'll show you that in an instant. Obviously, the endoscopist was not very, very happy. So, let's look at this. Clearly, there is invasion in the duplicated muscularis mycosae, so it's at least PT1A, and then you can see the neoplastic glands, and let's look at this area of concern here with the ink and some glands there. So, we did a cytokeratin, and you can see neoplastic glands right there at the ink. So, is this a positive deep margin? Well, it is not, and the reason for that is we need to take into account that once the specimen is fixed, frequently it can curl on itself, and we need to remember of the axis of a specimen. What I mean by this, this is the true vertical axis of the specimen, right? Mycosa muscularis, and you can see here on either side, the specimen folded. You see, instead of the horizontal axis, instead of being at 90 degrees, it's almost parallel because the specimen folded. So, clearly, there is invasion. Clearly, the invasion is there, but the deep, true deep margin is negative. The lateral margin is positive, and when everybody is happy, the endoscopics can go back, and the patient doesn't deserve surgical resection. Here is another example, just to make my point, and I lied for you for a minute. I said I will not talk about endoscopic submucosal dissection. Well, I will. This is an example of submucosal dissection, and just to show you the beauty of the specimen, and obviously, the key features of ESM versus EMR is that the resection goes much deeper, and obviously, we know that because we've got a submucosal esophageal glands. So, this is the submucosa. So, in this example, to make the same point here, higher magnification, you see the vertical axis. You see the neoplastic glands. You see, come there, it's at the level of a deep margin. It's not a rolled-up specimen, and it's also another beauty of endoscopic mucosal resection, the specimens are larger, they can be stretched much better, and they don't curl up the same way. How do we stage the specimen? So the AGCC subdivides mucosal and submucosal invasion by three levels. We'll talk only about submucosal invasion since submucosal evaluation is not easy on EMR. So PT1A is subdivided in M1, M2, and M3. M1 is in situ, which is something that we essentially don't use in the US. In the Western world will be high-grade dysplasia or carcinoma in situ, which obviously is not a terminology that we use. M2 will be invasion into the lamina propria that we use in Barrett's esophagus, we use in stomach, it's not like in colon, right? Remember those patients with M2 invasion have a risk of nodal invasion between 2.5 and 5 percent. And then M3 is extension into the muscular ischemicosis. However, remember that the muscular ischemicosis is duplicated. So let's look at this beautiful example, which we don't always see, of Barrett's esophagus. Now you see this is a receptor specimen, but to make the point. So mucosa, here the superficial aspect of the muscular ischemicosis, which is frequently duplicated and can extend with muscle bands toward the surface. So here the duplicated muscle muscular ischemicosis should not be interpreted as evidence of PT1A invasion, and therefore it's only high-grade dysplasia. Okay, so remember this, number one. Number two, the outer aspect of muscular ischemicosis, of this duplicated muscular ischemicosis, can be thickened. And if you have invasion there, remember that you have a duplicated muscular ischemicosis and this thick layer is not evidence of muscular ischemicosis. So this is not PT2, this is a PT1 cancer. Finally, remember that there is a space between the two layers of the muscular ischemicosis, and therefore this layer here is not, again, muscular ischemicosis propria. This is a lower aspect of the muscular ischemicosis, and therefore should not be mistaken for PT1B. Okay, so finally a couple of examples. What is the stage here? You see here is a little bit of fat, so I know this is the submucosa, but this is not, so we are above the muscular ischemicosis. This is still a PT1A adenocarcinoma and not a PT1B or a PT2. Okay, and here what is the stage again? You can see here, so there is a lot of adipose tissue, large vessels, some glands, large vessels, adipose tissue, glands, equals submucosa. You have invasive tumor here, this is submucosal adenocarcinoma. So this is it for me tonight. All right. Thank you, Dr. Lowers. It's such a beautiful illustration, and it's so logical you make something that is so complicated, so easy to understand. At the same time, you're very realistic and practical. Let us know that not everything is black and white, but it's not black and white, let us know that not everything is black and white. There's a lot of judgment into all this. So let's see, do we have questions in the audience? While we're waiting for the questions to come in, let me ask Dr. Lowers some questions. In your professional life, what do you, what, when you talk about the dysplasia of barrytes esophagus, what's, in one or two sentences, you have to summarize how you feel about this topic, what's the take-home message we should know? Well, good evening. Can you hear me? Yes. Perfect. Well, thank you for anyone who has been checking in tonight. So my interest in dysplasia in barrettes and in the stomach is, and you know, I'm sure there is the same thing in other field of GI pathology, but I forgot everything about GI pathology, is that clearly that's where we can really contribute significantly to the management of a patient. You and I know, obviously working in a cancer center, we confirm diagnosis, we make the diagnosis, but, you know, the diagnosis of cancer, now the subtyping and precision medicine may modify the treatment, but, you know, the train has left the station, so to speak. Dysplasia is really at the stage where a proper evaluation of dysplasia, working closely with our clinical colleagues, can clearly save the patient and not only themselves, but their organs, depending where the organs, by proper evaluation and management. So that's why I'm very interested, and because it's a stage obviously before cancer, so research-wise can help us to understand the next stage. So that's why my interest in dysplasia. Very good, because I all remember the GI group have this multi-head scope, everybody put their heads together to discuss if there is a dysplasia, low grade or high grade, and it's always a group consent. So one question is asking about, they loved your presentation, they think the PowerPoint is just beautiful. They ask, will the PowerPoint be shared? So what's your answer? Yeah, you know, I can share anything. Oh, very good. You tell me where to send it, or Amber, who has been wonderful in guiding me, will tell me what to do, and I will. All right, that's great. So that's a promise. On the other hand, this lecture is being recorded, so it's going to be on the FSP website. So if you're a member, and you can review this on demand, unlimited time. And on the other hand, Dr. Lowers has generously agreed to have this PDF of the PowerPoint archived for us, so that's very, very nice. So this is another question from Dr. Patel. What is the impact of misdiagnosis of intramucosal adenocarcinoma as a high grade dysplasia? Is management different or the same? No, no. So as I mentioned before, and I thank you for the question, because I can reemphasize that. So clearly, since there's been this recognition of, and the use rather, not the recognition, the development of endoscopic mucosal resection, you know, once you make the diagnosis, if a lesion can be recognized, the endoscopist will, whether you work or may refer it to a center where they will, they will do an endoscopic mucosal resection, okay? And at that stage, there are a couple of things, great value with endoscopic mucosal resection, and we've shown that some years ago, is if you look at inter-observer variability on biopsies, where we know we all do an okay job, but you know, we are not perfect. The degree of inter-observer variability is much better on an endoscopic mucosal resection or endoscopic sub-mucosal resection, just because we have much more tissue and we show statistically, my group before and other studies, that we are much better. So that's one of the value of endoscopic mucosal resection, our diagnosis is much more, is better, quote unquote. The second thing is that the discrepancy between high-grade and intramucosal cancer is at a very limited stage of patients who may have already an enlarged lymph node. So when they're going to do the endoscopy, before that, they should have mostly, they would have had an endoscopic ultrasound. If at the stage of endoscopic ultrasound, there is an enlarged lymph node, you know, one centimeter and above, then they're going to take into account a little bit more closely the diagnosis that you have made, and they may decide to jump immediately to surgery or maybe sometimes neuroadjuvant therapy and surgery. So it may not have been surgery, but neuroadjuvant therapy. So there is this subgroup of patients where if there is enlarged lymph node, then our diagnosis, high-grade versus intramucosal, will become much more crucial. But if not, you know, I will be the first one to say that, you know, it's shades of gray. So there are cases where I will feel comfortably, no, this is not high-grade dysplasia, it's definitely intramucosal because of A, B, C, or D. But other cases, you know, how much do you agree there is interlacing of a gland? How much of a withering? So, you know, anyone who tells you it's black and white, I don't think so. Sometimes it's black, sometimes it's black, but in many instances, it's more of a gray zone. And, you know, it's something that we need to to live with. Okay. Thank you. There's another audience. And again, thank you very much for sharing this outstanding presentation. The question is, Dr. Lowers, do you grade basal crypt dysplasia? So, no, I do not. And actually, so I said basal gland or basal crypt dysplasia. And there's been a lot of discussion. It's not very settled yet. Even some of the most strongest proponent of this I have somehow backed off. When you see basal crypt dysplasia, it should be seen as a red flag. And as a red flag that the patient is at risk of developing high-grade dysplasia, or as I think my presentation was not very clear on that, I may have already high-grade dysplasia of a traditional, sorry, high-grade dysplasia of a traditional type somewhere else. So, if you look at the original paper, I think 87% of the patients already had had dysplasia in previous, high-grade dysplasia in previous biopsy, or at the time of a diagnosis of basal crypt or basal gland dysplasia. So, it should be seen as a red flag. Make sure that your endoscopies goes back with biopsy exhaustively the patient. And then more likely than not, a traditional dysplastic focus and more likely of high-grade will be detected. And then we all will feel better. Thank you. So, another question on basal crypt dysplasia. The question is, do you use p53? So, I didn't want to talk about p53. You're forcing me to talk about p53. So, the reason is if you read many reviews and many statements by some societies, they say do not use p53. And if I tell you I don't use it, I'll be a liar. P53, and actually there is a very nice paper that was done by some Australian colleagues recently. The problem about p53 is that it needs to be well-performed and we need to use it rightfully. And like anything else, not a single immuno should guide your diagnosis. It should always be driven by your morphologic evaluation. So, let me answer to your question. Do I use p53 specifically for crypt dysplasia? No. Do I use p53 for dysplasia in the general context of barrettes? Sometimes. And the way I use it is fourfold. Number one, you need to remember that normal barrettes can have p53 positivity. It's going to be faint and patchy, but I've seen some of our colleagues make mistakes. Then low-grade dysplasia p53, and then there is this very nice paper, and I can give a reference later to Amber. It's a paper that came from Australia by Dr. Priyanti Kumar-Singhe from the University of Western Australia, where they have demonstrated that it's not only the staining, but also the distribution of the staining. So, low-grade dysplasia will be more of a stronger stain toward the base of the epithelium. High-grade dysplasia is stronger more toward the surface, and that distribution is very, very helpful. But you have also to remember that you have a neural phenotype that sometimes p53 mutations yield to a negative, to the absence of protein formation, and therefore p53 negative does not always mean not dysplastic. So, again, you have to be very, very cautious with this. But that's why I like Ka67. You know, let me advertise my thing, because Ka67 is much less ambivalent in terms of staining, and clearly, if there is no surface staining, but, you know, it means that biologically this epithelium still has some control, and it was sometimes in most difficult cases, as I've shown you, I use p53, and sometimes in some of the consoles that I receive, I use it to make the point to our colleagues. Okay. Thank you. So, we're close to the end. Let me ask the one last question. So, from your biosketch, we see that you published 400 some review articles, peer-reviewed articles, book chapters, and several books. So, question number one is, what's your secret of success? Second is, what's the next book that is coming out of you? Thank you. A secret of success to, well, to be stubborn, but it's not a good quality. I think for the young people, if I can say that, if any young resident on the call is to be, not to accept any dogma, and I think that every time you see something in a book, if it doesn't fit what you see on the other slides, just be ready to maybe question the dogma, and then you start to write a paper, and then you write a second, and then you write another one, and eventually you may have a fair number, but the number is not important. That's the quality. So, I'm not sure that mine are all good. I know of people who have less papers, but theirs are much better than mine. So, what is the next book coming out from Dr. Lowers? The next book, well, it won't be a New York Times bestseller, but now there's a biopsy book which is coming out soon with Dr. Wallace, who is an endoscopist at the Mayo Clinic in Jacksonville, and Dr. Klauditz from Germany, and the idea is to put the expertise of pathologists and clinicians in a simple biopsy book, which is coming out very soon, and to try to put together, and not to go into too much esoteric thing, but to guide the diagnosis from the pathologic point of view, but also with a little angle from the clinicians, because, as you know, the clinicians are not interested sometimes, you know, blah, blah, blah. They want a simple answer to a simple clinical question, which is going to guide the management of the patient. Thank you so much. On behalf of the Florida Society of Pathologists, I'd like to thank the audience who take your evening, spend the time with us to learn about the GI pathology. I'd like to thank Dr. Lowers for his expertise and his outstanding lectures. I'd like to thank our management group, Amber Nace and Aaron Corrales for their excellent support, and I'd like to thank our educational committee who planned these CME lectures to benefit our member. With that said, thank you, everyone. Have a great evening. See you next time. Bye. Thank you. Bye-bye.

Barrett's esophagus

diagnosis

dysplasia

endoscopic resection

biopsy assessment

Dr. Gregory Lowers

Moffitt Cancer Center

virtual CME lecture

pathology