WEBVTT 00:00:00.466 --> 00:00:00.700 well, 00:00:00.700 --> 00:00:03.800 thank you so much for joining us for this, presentation. 00:00:03.800 --> 00:00:06.800 And, I'm really excited to be here and talk to you 00:00:06.800 --> 00:00:09.800 about something that I feel very passionate about. 00:00:09.933 --> 00:00:13.266 We'll talk about lymphocytes and, in particular 00:00:13.266 --> 00:00:16.500 the lymphocytes and peripheral blood and how, 00:00:17.266 --> 00:00:19.800 our approach to, 00:00:19.800 --> 00:00:22.800 those little guys can really change the patient's care. 00:00:24.666 --> 00:00:27.100 So, you've probably seen the objectives 00:00:27.100 --> 00:00:30.766 that were posted on the, you know, that, invitation. 00:00:30.766 --> 00:00:31.933 So we're going to skip those. 00:00:31.933 --> 00:00:36.600 But I wanted to, let you know that we will go into some clinical cases here. 00:00:36.866 --> 00:00:41.666 And I have, changed, you know, slightly modified laboratory information. 00:00:41.666 --> 00:00:43.433 So those cases are not traceable. 00:00:43.433 --> 00:00:46.433 But this change is not going to affect the, 00:00:46.733 --> 00:00:49.733 educational importance of the case. 00:00:50.500 --> 00:00:53.233 And I would like to start with this. 00:00:53.233 --> 00:00:57.633 I think a very beautiful, drawing that was done by Cynthia Blackhall. 00:00:57.966 --> 00:00:59.833 So I spent some time in New York City. 00:00:59.833 --> 00:01:03.933 And when you go to and from work on the subway, there's there's a lot of time. 00:01:03.933 --> 00:01:08.300 And, you'll, you look around and they actually had this beautiful, 00:01:08.533 --> 00:01:11.500 very long, poster on the subway. 00:01:11.500 --> 00:01:14.500 And as you see, there are a lot of different people, 00:01:14.966 --> 00:01:18.300 different faces, different clothes, different styles, different, 00:01:18.666 --> 00:01:19.833 you know, interactions. 00:01:19.833 --> 00:01:22.900 And I thought it was a very good picture to, show 00:01:23.233 --> 00:01:27.233 the diversity of our, society. 00:01:27.233 --> 00:01:31.166 And this is a kind of a diversity, approach that I would like to apply 00:01:31.166 --> 00:01:32.466 to the lymphocytes as well. 00:01:35.466 --> 00:01:36.466 So let's just start 00:01:36.466 --> 00:01:39.466 with very basic concepts. 00:01:39.533 --> 00:01:42.233 As we know, lymphocytes are very important cells 00:01:42.233 --> 00:01:45.233 and they are part of the immune system. 00:01:45.266 --> 00:01:48.700 Whereas the majority of lymphocytes are actually participating 00:01:48.700 --> 00:01:52.933 in what we call adaptive immune system there, there are some subsets 00:01:52.933 --> 00:01:56.800 that I also important for, the innate immune system. 00:01:57.633 --> 00:02:02.566 And if we look at the peripheral blood smear or as the CBC results, 00:02:02.566 --> 00:02:06.500 we will notice that lymphocytes are a very important 00:02:06.500 --> 00:02:10.166 and very numerous, subpopulation of white blood cells. 00:02:10.633 --> 00:02:13.633 And then if we compare, CBCs, 00:02:14.433 --> 00:02:17.433 from kids versus adults, we'll also notice 00:02:17.800 --> 00:02:21.366 that, the children usually have, higher, 00:02:22.133 --> 00:02:24.833 relative number of lymphocytes. 00:02:24.833 --> 00:02:28.333 So there are three major types of lymphocytes in the peripheral blood. 00:02:29.333 --> 00:02:32.633 Those are B-cells, T-cells and NK cells. 00:02:33.100 --> 00:02:36.500 So there is something very special about the NK cells in here. 00:02:36.500 --> 00:02:38.800 The are in this picture at the very bottom. 00:02:38.800 --> 00:02:43.600 So the NK cells actually do not need any antigen exposure for them to function. 00:02:43.600 --> 00:02:47.100 So they are, a part of the innate immune system, 00:02:47.466 --> 00:02:51.033 whereas the B cells and the vast majority of T cells actually need 00:02:51.033 --> 00:02:55.066 the antigen, exposure before they can, properly function. 00:02:58.433 --> 00:03:00.433 Now, if we look at, 00:03:00.433 --> 00:03:06.233 the reasons why we call those main subsets as B cells, we will notice 00:03:06.233 --> 00:03:09.700 that there are a lot of differences, but there are a lot of common things as well. 00:03:10.600 --> 00:03:12.866 So the B cells are called B cells 00:03:12.866 --> 00:03:16.900 because they're were initially described in the, Porsche Fabrica. 00:03:16.900 --> 00:03:19.300 This is the organ in birds. 00:03:19.300 --> 00:03:21.266 And it was those 00:03:21.266 --> 00:03:25.233 cells were found to be, developing in that organ. 00:03:25.233 --> 00:03:27.333 That's why they're called B cells. 00:03:27.333 --> 00:03:30.833 But, we also know that we do not have that organ in humans. 00:03:31.400 --> 00:03:35.333 In fact, the B cells in humans mature in the bone marrow. 00:03:35.333 --> 00:03:38.066 So it's a very easy, thing to remember. 00:03:38.066 --> 00:03:41.066 B cells come from the bone marrow. 00:03:41.066 --> 00:03:45.566 In contrast, T cells, they mature in the same as this white. 00:03:45.600 --> 00:03:47.033 That's why they're called T cells. 00:03:48.033 --> 00:03:50.300 Now, the difference between the B and the T cell 00:03:50.300 --> 00:03:54.333 populations is what kind of receptors they express on their surface. 00:03:55.533 --> 00:03:59.000 In many ways those receptors have a lot of common features. 00:03:59.166 --> 00:04:03.833 And if we look at the B cell receptor, we'll see that the, kind of main role 00:04:03.833 --> 00:04:07.500 belongs to the immunoglobulin molecule that's expressed on the surface. 00:04:08.233 --> 00:04:11.766 So the immunoglobulin molecule actually interacts with the antigen. 00:04:12.400 --> 00:04:15.400 And then we also have some ecosystem utility 00:04:15.800 --> 00:04:18.800 Co stimulatory molecules that 00:04:19.933 --> 00:04:22.300 facilitate the signal transduction. 00:04:22.300 --> 00:04:25.833 Among those, we'll see that there are immunoglobulins being and alpha 00:04:26.366 --> 00:04:29.066 that we also know as CD 00:04:29.066 --> 00:04:32.066 7 to 9 A and CD 7 to 9 B 00:04:32.733 --> 00:04:34.333 as well as CD 21. 00:04:34.333 --> 00:04:37.333 And there's another molecule that, 00:04:37.400 --> 00:04:39.400 that forms 00:04:39.400 --> 00:04:42.533 a complex with seeded 21, we call it CD 19. 00:04:43.600 --> 00:04:45.033 So in order for us 00:04:45.033 --> 00:04:50.000 to call a cell a B cell, we need to make sure that those cells 00:04:50.000 --> 00:04:54.400 express it in 19 and also some other B cell markers. 00:04:54.600 --> 00:04:57.400 Among those would be 22 to 22 00:04:57.400 --> 00:05:00.400 and CD is 79 A and B. 00:05:01.566 --> 00:05:03.533 Now if we look at the surface 00:05:03.533 --> 00:05:07.100 of the T cell we'll find a very similar structure. 00:05:07.100 --> 00:05:10.100 But in this case we'll call it T cell receptor. 00:05:10.900 --> 00:05:13.900 It also has this hetero dimer 00:05:13.933 --> 00:05:16.533 consisting of two subunits that kind of 00:05:16.533 --> 00:05:19.533 looks like immunoglobulin on the B cells. 00:05:19.533 --> 00:05:24.700 So depending on what kind of subunits this hetero dimer consists of, 00:05:24.700 --> 00:05:29.133 we will, step, classify our T cells into gamma delta subcategory. 00:05:29.166 --> 00:05:33.466 So they have this gamma and delta subunits or alpha beta T cells. 00:05:33.900 --> 00:05:37.200 And alpha beta T cells are definitely more numerous in gamma delta. 00:05:38.466 --> 00:05:41.400 Now there are also other 00:05:41.400 --> 00:05:45.966 proteins that help to transduced a signal. 00:05:46.100 --> 00:05:49.600 And those would be, the subunits of the CD3 protein. 00:05:50.000 --> 00:05:53.933 And that's a protein that will also make us call a cell it T cell. 00:05:55.300 --> 00:05:58.300 And then depending on other molecules on the surface of the T cells, 00:05:58.533 --> 00:06:01.566 we can also classify them into CD4 positive 00:06:01.566 --> 00:06:04.566 CD8 positive subpopulations. 00:06:05.066 --> 00:06:10.766 And once again, when we look at the flow cytometry, we will identify T cells 00:06:10.766 --> 00:06:14.833 by their expression of CD3 as well as some other markers 62 CD 00:06:14.900 --> 00:06:17.900 five and 67. 00:06:18.966 --> 00:06:21.400 So very briefly on the B-cell development. 00:06:21.400 --> 00:06:24.733 So once again we said that the initial or antigen, 00:06:26.266 --> 00:06:29.933 independent maturation of the B cells happens in the bone marrow. 00:06:30.533 --> 00:06:33.400 And there's one very important process that takes place. 00:06:33.400 --> 00:06:36.133 We call it immunoglobulin gene rearrangement. 00:06:36.133 --> 00:06:41.166 So this is when the B cell decides to create a functional immunoglobulin 00:06:41.733 --> 00:06:44.400 molecule and express it on the surface. 00:06:44.400 --> 00:06:48.266 When that process is done, the B cell is ready to go out in the circulation 00:06:48.266 --> 00:06:53.100 and then go into the lymph nodes and other lymphoid tissues around the body. 00:06:54.233 --> 00:06:57.300 So within the bone marrow that immature B-cell 00:06:57.300 --> 00:07:01.166 in the normal individual would be called matagal. 00:07:01.600 --> 00:07:04.500 And this is what he Madigan's look like under the microscope. 00:07:04.500 --> 00:07:07.433 So the marigolds should not be seen in the peripheral blood 00:07:07.433 --> 00:07:09.866 right there in the bone marrow. 00:07:09.866 --> 00:07:13.833 But as the B-cell matures, it becomes mature B-cell. 00:07:14.600 --> 00:07:17.800 Then it goes into the circulation and depending on its fate, 00:07:18.133 --> 00:07:21.133 it may, meet the right antigen. 00:07:21.566 --> 00:07:26.333 And in the lymph node, it can form what we call secondary lymphoid follicle, 00:07:26.800 --> 00:07:29.766 where two other important processes take take place. 00:07:29.766 --> 00:07:32.766 Those are somatic hyper mutation and isotype switching. 00:07:32.766 --> 00:07:37.433 So after this very tough school at the germinal center, 00:07:37.466 --> 00:07:40.466 the B-cell is actually capable of secreting, 00:07:41.033 --> 00:07:44.133 immunoglobulins that have very high affinity to the antigen. 00:07:44.133 --> 00:07:47.766 But at the same time they do not have high affinity to your own tissues. 00:07:48.466 --> 00:07:51.833 And this is the picture of this is what the germinal centers 00:07:51.833 --> 00:07:53.500 actually look like under the microscope. 00:07:55.700 --> 00:07:57.900 Now the T-cell development, 00:07:57.900 --> 00:08:00.900 also starts in the bone marrow, but very early, 00:08:01.300 --> 00:08:04.533 at the very earliest stages, those cells would migrate into thymus. 00:08:04.866 --> 00:08:09.433 And then the antigen dependent, maturation will happen in thymus, 00:08:09.700 --> 00:08:14.233 and the T cells will also circulate in the peripheral blood, going from one 00:08:15.133 --> 00:08:18.433 organ to another organ and function. 00:08:21.700 --> 00:08:25.166 So flow cytometry is a great technique, 00:08:25.766 --> 00:08:28.766 to differentiate the lymphocytes. 00:08:29.400 --> 00:08:32.500 So if we look at kind of the 00:08:33.566 --> 00:08:36.066 main, plot where we look 00:08:36.066 --> 00:08:41.166 at the CD 45 expression versus side scatter, we will find that the lymphocytes 00:08:41.333 --> 00:08:46.633 form a very nice and tight cluster that is CD 45 pretty brightly positive. 00:08:46.633 --> 00:08:49.633 And side scatter is usually on the low side. 00:08:49.733 --> 00:08:53.166 And then if we apply different, immuno markers 00:08:53.166 --> 00:08:56.200 we can also within that within those lymphocytes, 00:08:56.333 --> 00:09:01.333 we can also identify the B-cells which would be 20 positive and CD 19 positive. 00:09:02.166 --> 00:09:04.633 We can easily detect T 00:09:04.633 --> 00:09:07.633 cells which would be CD3 positive. 00:09:08.033 --> 00:09:11.033 We can also in this plot see the NK cells. 00:09:11.033 --> 00:09:16.066 So NK cells are not the T cells and they do not have surface CD3. 00:09:16.333 --> 00:09:20.633 And therefore on this plot they will be right here CT7 positive CD3 negative. 00:09:21.266 --> 00:09:24.000 And then within within the T cell population 00:09:24.000 --> 00:09:28.633 we can also separate them into CD4 positive cells and CD8 positive cells. 00:09:30.533 --> 00:09:30.966 All right. 00:09:30.966 --> 00:09:32.800 So where's the problem here. 00:09:32.800 --> 00:09:35.800 Now if we look at the peripheral blood smear 00:09:36.500 --> 00:09:39.100 all those subpopulations of cells 00:09:39.100 --> 00:09:41.700 will look very very similar. 00:09:41.700 --> 00:09:44.700 And we cannot distinguish them by morphology. 00:09:46.733 --> 00:09:48.166 More than that, 00:09:48.166 --> 00:09:51.166 if you look at normal lymphocytes 00:09:51.166 --> 00:09:55.300 that their morphology within the same patient can be very, very different. 00:09:55.900 --> 00:10:00.966 So that poses a lot of, difficulties in the way we interpret the morphologic 00:10:00.966 --> 00:10:04.266 features of the lymphocytes in any particular, person. 00:10:04.700 --> 00:10:10.666 So, those lymphocytes were actually identified in, in, healthy individual. 00:10:10.666 --> 00:10:13.366 And as you see, there's a lot of different variability there. 00:10:13.366 --> 00:10:17.433 Smaller cells, larger cells, the nuclear features are different. 00:10:17.433 --> 00:10:20.433 The cytoplasm is also different. 00:10:22.866 --> 00:10:23.266 All right. 00:10:23.266 --> 00:10:26.266 So let's look at the workflow in the clinical lab. 00:10:26.800 --> 00:10:31.300 The lab receives the specimen from the patient for the CBC. 00:10:31.900 --> 00:10:34.900 And depending on the rules that are implemented in the lab, 00:10:35.366 --> 00:10:38.766 the subset of the smears, depending on the CBC 00:10:38.766 --> 00:10:42.100 results will also be submitted for the microscopic evaluation. 00:10:42.866 --> 00:10:45.400 Now, this step is extremely important 00:10:45.400 --> 00:10:49.266 because, laboratory scientists who looks at those smears, 00:10:50.233 --> 00:10:52.333 will, use 00:10:52.333 --> 00:10:56.066 her or his judgment and, potentially 00:10:56.100 --> 00:11:00.166 may lead to some additional workup if they find some abnormal findings. 00:11:01.533 --> 00:11:04.700 So, the additional workup is usually very expensive tests. 00:11:05.000 --> 00:11:07.033 So we do not want to overrun them. 00:11:07.033 --> 00:11:09.833 At the same time, we do not want to miss those patients 00:11:09.833 --> 00:11:13.533 that might benefit from, those tests from actually running those. 00:11:14.200 --> 00:11:17.966 Therefore, the laboratory team that is responsible 00:11:17.966 --> 00:11:20.966 for the microscopy in the clinical lab is extremely important. 00:11:21.633 --> 00:11:24.900 So that team consists of laboratory technologists and laboratory scientists 00:11:25.200 --> 00:11:26.833 as well as pathologists. 00:11:26.833 --> 00:11:30.666 And in the setting of er up and the University of Utah, we have 00:11:31.466 --> 00:11:34.166 attending pathologists as well as residents 00:11:34.166 --> 00:11:37.166 who are learning. 00:11:37.433 --> 00:11:39.200 Therefore our interaction 00:11:39.200 --> 00:11:42.200 is extremely important in the settings. 00:11:42.300 --> 00:11:45.400 So what sets laboratory scientists apart is that, 00:11:46.333 --> 00:11:49.333 they are being trained in morphology 00:11:49.766 --> 00:11:52.866 and on average, a person, a laboratory scientist 00:11:52.866 --> 00:11:55.666 who works at the bench looking at the sneers, 00:11:55.666 --> 00:11:58.433 he or she will probably see many more smears a day 00:11:58.433 --> 00:12:01.433 than the pathology resident would see it a month. 00:12:02.000 --> 00:12:04.766 So, laboratory scientists, 00:12:04.766 --> 00:12:08.800 you know, by definition, have much better exposure to morphology, 00:12:09.066 --> 00:12:11.833 and therefore they become extremely important tool 00:12:11.833 --> 00:12:15.300 in recognizing abnormal features in the lymphocytes, particularly. 00:12:16.433 --> 00:12:17.133 And now we have 00:12:17.133 --> 00:12:20.133 pathologists, including attendings and residents. 00:12:20.333 --> 00:12:23.300 So our role in this whole, 00:12:23.300 --> 00:12:27.600 workflow is to put the morphologic findings into the clinical setting. 00:12:28.000 --> 00:12:30.733 So what we see under the microscope actually 00:12:30.733 --> 00:12:34.000 makes sense when we put it in clinical context. 00:12:34.400 --> 00:12:37.000 And we also will provide, 00:12:37.000 --> 00:12:37.500 you know, 00:12:37.500 --> 00:12:41.500 the appropriate level of communication between the laboratory and the clinician. 00:12:42.000 --> 00:12:46.466 So the role of those, professionals in the process is different. 00:12:46.733 --> 00:12:49.733 But at the same time, we need to realize that it should be, 00:12:50.100 --> 00:12:53.100 it should be a team effort. 00:13:00.133 --> 00:13:01.300 So let's talk 00:13:01.300 --> 00:13:04.300 a little bit about, what do we do when, 00:13:05.166 --> 00:13:07.333 we find that the number of lymphocytes 00:13:07.333 --> 00:13:10.333 in the peripheral blood is not normal. 00:13:10.500 --> 00:13:14.166 So lymphocyte ptosis, is actually a more, 00:13:14.700 --> 00:13:17.700 common, finding the lymphocytic leukemia 00:13:18.033 --> 00:13:21.866 and lymphocyte doses can be subdivided into two main categories. 00:13:22.000 --> 00:13:26.800 It could be benign or reactive lymphocyte ptosis as well as malignant lymphocytes. 00:13:27.600 --> 00:13:30.533 So when we think about the benign lymphocyte ptosis 00:13:30.533 --> 00:13:34.633 we should always think about infection, particularly virus viral infection. 00:13:35.200 --> 00:13:39.933 Sometimes certain drugs can cause increased, lymphocyte in the blood. 00:13:41.366 --> 00:13:44.566 There are other conditions that we, see. 00:13:44.566 --> 00:13:46.200 Not not that commonly. 00:13:46.200 --> 00:13:51.166 Those would be transient lymphocyte ptosis in patients, usually after surgery. 00:13:51.900 --> 00:13:55.000 Or it could be persistent polyclonal lymphocyte ptosis 00:13:55.000 --> 00:13:58.666 that is, associated with, women 00:13:58.666 --> 00:14:01.666 and usually those who are smokers, 00:14:02.733 --> 00:14:05.566 chronic infections, chronic, 00:14:05.566 --> 00:14:10.533 long lasting autoimmune disorders may also, produce lymphocyte ptosis. 00:14:10.833 --> 00:14:13.700 And post-transplant marrow recovery is also notorious 00:14:13.700 --> 00:14:16.700 for increased lymphocyte number 00:14:17.466 --> 00:14:19.733 and then malignant lymphocyte ptosis. 00:14:19.733 --> 00:14:22.733 Is usually associated either with 00:14:23.633 --> 00:14:27.066 overt malignancy like leukemia, lymphoma, or sometimes it could be that pre 00:14:27.066 --> 00:14:31.033 malignant process, such as monoclonal B-cell lymphocyte ptosis. 00:14:32.566 --> 00:14:34.266 Now lymphocyte apnea. 00:14:34.266 --> 00:14:36.366 Once again we do not see that often. 00:14:36.366 --> 00:14:42.166 But when when we encounter it there are several causes for it. 00:14:42.166 --> 00:14:45.033 And it could be some nutritional deficiencies. 00:14:45.033 --> 00:14:48.233 It could be immune deficiencies. 00:14:48.666 --> 00:14:52.433 Again, autoimmune disorders, infections, stemming disease. 00:14:52.433 --> 00:14:55.833 And one we always need to remember is I estrogenic 00:14:56.700 --> 00:15:00.400 either administration of immunosuppressive therapy or, 00:15:02.000 --> 00:15:05.000 also, bone marrow transplantation. 00:15:06.133 --> 00:15:06.400 All right. 00:15:06.400 --> 00:15:07.900 So let's go into morphology. 00:15:07.900 --> 00:15:10.600 Let's, start talking about normal game. 00:15:10.600 --> 00:15:14.800 Because when we understand normal is going to be easier to, for us to see abnormal. 00:15:15.433 --> 00:15:18.433 So mature lymphocytes, this is what they look like. 00:15:19.966 --> 00:15:22.966 They can be of variable size and, 00:15:24.133 --> 00:15:26.733 considering that, the IC 00:15:26.733 --> 00:15:29.733 guidelines actually recommends distinguishing 00:15:29.733 --> 00:15:33.133 small lymphocytes from large lymphocytes just depending on their size. 00:15:33.733 --> 00:15:36.366 And the nucleated cytoplasmic ratio is variable, 00:15:36.366 --> 00:15:38.200 but it's usually on the lower side. 00:15:38.200 --> 00:15:41.166 And once again, to 00:15:41.166 --> 00:15:43.733 to identify or to measure the NC ratio, 00:15:43.733 --> 00:15:47.566 we'll look at the diameter of the nucleus as opposed to the cytoplasm. 00:15:49.300 --> 00:15:51.100 The nucleus is usually around sometimes 00:15:51.100 --> 00:15:54.100 and it can be oval or somewhat indented. 00:15:54.300 --> 00:15:55.200 And the chromatin 00:15:55.200 --> 00:15:59.233 is a very important feature to look for because in a mature 00:15:59.233 --> 00:16:03.100 lymphocyte, the chromatin is going to be, very dense and plump. 00:16:04.066 --> 00:16:06.500 The nuclei are usually inconspicuous 00:16:06.500 --> 00:16:09.500 and the cytoplasm does not have any granules. 00:16:11.866 --> 00:16:12.333 All right. 00:16:12.333 --> 00:16:13.600 Another subpopulation 00:16:13.600 --> 00:16:17.400 that we commonly see, we call them large granular lymphocytes. 00:16:18.266 --> 00:16:22.400 And from the name you can already, know what they should look like. 00:16:22.600 --> 00:16:25.600 So there are large cells. 00:16:25.666 --> 00:16:29.900 They have a lot of cytoplasm much more than the small mature lymphocytes. 00:16:30.566 --> 00:16:35.200 And the cytoplasm has a lot or sometimes, a few of the, 00:16:35.800 --> 00:16:38.900 very coarse purple granules that contain for enzyme B, 00:16:40.633 --> 00:16:42.633 the nucleus, however, 00:16:42.633 --> 00:16:45.166 still looks like a normal, mature lymphocytes. 00:16:45.166 --> 00:16:48.166 So it's, clumped chromatin and no nucleolus. 00:16:52.566 --> 00:16:55.233 Now if we look into, 00:16:55.233 --> 00:16:57.966 those lgl and, and apply flow 00:16:57.966 --> 00:17:00.966 cytometry, we will see that those cells 00:17:01.266 --> 00:17:04.366 I composed of two different subsets of lymphocytes, 00:17:05.433 --> 00:17:09.900 some of those algos will be NK cells that are CD3 negative. 00:17:10.233 --> 00:17:15.066 The surface CD3 negatives and others would be cytotoxic 00:17:15.133 --> 00:17:19.300 T cells that are CD8 positive and CD3 positive. 00:17:20.700 --> 00:17:22.833 And so the normal individuals 00:17:22.833 --> 00:17:26.666 may have, up to 20% of LDL in their peripheral blood. 00:17:27.000 --> 00:17:29.233 And if that's the case, 00:17:29.233 --> 00:17:32.433 the ICA guidelines do not, 00:17:32.866 --> 00:17:36.033 recommend reporting that subpopulation separately. 00:17:36.033 --> 00:17:39.033 And they're just the count is included in the lymphocyte count. 00:17:39.866 --> 00:17:44.033 However, we do see, increased lgl since some reactive conditions 00:17:44.033 --> 00:17:48.133 as well as in your, in neoplastic, conditions as well. 00:17:48.933 --> 00:17:51.200 So, viral infections, 00:17:51.200 --> 00:17:56.166 autoimmune diseases may give you relative and absolute increase of lgl 00:17:56.500 --> 00:18:00.833 as well as some forms of, leukemia lymphomas, particularly t Lgl, 00:18:01.366 --> 00:18:04.766 or some NK type LGA leukemia lymphomas 00:18:05.200 --> 00:18:10.566 and if the laboratory sees that the percentage of those lgl is increased, 00:18:10.566 --> 00:18:14.900 and sometimes it's reasonable to report those in a separate category. 00:18:16.266 --> 00:18:20.066 And again, it's really difficult just based on the CBC counts 00:18:20.066 --> 00:18:23.100 as well as morphology, to distinguish the, 00:18:23.466 --> 00:18:26.233 reactive versus neoplastic process. 00:18:26.233 --> 00:18:28.833 However, we know that usually in 00:18:29.800 --> 00:18:33.033 in neoplasm, the absolute number of LGS, 00:18:33.666 --> 00:18:36.666 over is over 2000 per microliter. 00:18:39.433 --> 00:18:39.866 All right. 00:18:39.866 --> 00:18:42.766 Let's go into, 00:18:42.766 --> 00:18:45.766 more, into a scarier, section of, 00:18:46.966 --> 00:18:48.066 normal lymphocytes. 00:18:48.066 --> 00:18:51.066 So we call those populations reactive lymphocytes. 00:18:51.066 --> 00:18:53.900 And so reactive lymphocytes is a commonly accepted 00:18:53.900 --> 00:18:56.900 and recommended term for this kind of cells. 00:18:57.400 --> 00:19:01.100 There have been a lot of different names that would be associated 00:19:01.100 --> 00:19:04.433 with this subpopulation, which can be very, very confusing. 00:19:04.866 --> 00:19:09.166 And even currently if you go from lab to lab, the terminology really differs. 00:19:09.666 --> 00:19:13.633 And, you know, other names I put here are variant lymphocytes. 00:19:13.633 --> 00:19:17.733 Some people call them abnormal lymphocytes activated atypical down 00:19:17.733 --> 00:19:21.300 your cells of different subtypes, immuno blasts and so forth. 00:19:21.700 --> 00:19:24.700 So there is a, you know, big, 00:19:26.266 --> 00:19:28.733 inconsistency in the way those, 00:19:28.733 --> 00:19:32.233 those subpopulations can be reported, between the labs. 00:19:33.866 --> 00:19:35.466 So, the reactive 00:19:35.466 --> 00:19:38.666 lymphocyte, once again, this is the recommended term, 00:19:40.133 --> 00:19:45.400 and those are the variant or abnormal looking lymphocytes 00:19:45.833 --> 00:19:48.833 that represent a reactive process. 00:19:49.133 --> 00:19:52.500 The alternative term for the neoplastic process 00:19:52.500 --> 00:19:55.500 would be abnormal lymphocytes. 00:19:57.166 --> 00:19:59.100 So, the, 00:19:59.100 --> 00:20:03.866 reactive lymphocytes, once again, they may be seen in, viral infections. 00:20:04.333 --> 00:20:08.300 And, with that said, we always remember even seeing the infection 00:20:08.833 --> 00:20:11.833 as well as some drug reactions and, 00:20:11.933 --> 00:20:14.933 a big list of other conditions. 00:20:16.566 --> 00:20:16.900 All right. 00:20:16.900 --> 00:20:21.000 So here is, here are pictures of lymphocytes. 00:20:21.000 --> 00:20:23.566 I, took, 00:20:23.566 --> 00:20:25.566 from one of the cases I had 00:20:25.566 --> 00:20:28.066 and I tried to sub classify them into that 00:20:28.066 --> 00:20:31.066 older, subcategories. 00:20:31.100 --> 00:20:35.233 So the most common type of what we call reactive lymphocytes 00:20:35.533 --> 00:20:39.100 is what we used to call, downy type two cells. 00:20:39.633 --> 00:20:41.133 So those are larger cells. 00:20:42.933 --> 00:20:45.400 They have round or they could 00:20:45.400 --> 00:20:48.400 be somewhat, they could have somewhat irregular nucleus. 00:20:48.433 --> 00:20:50.433 But once again, pay attention to chromatin. 00:20:50.433 --> 00:20:51.933 Chromatin usually stays 00:20:51.933 --> 00:20:55.833 quite mature clumped, but sometimes it can be more delicate. 00:20:55.833 --> 00:20:59.200 And even nuclei they can be appreciated. 00:21:00.466 --> 00:21:03.433 Now the cytoplasm is abundant. 00:21:03.433 --> 00:21:05.200 Can vary in color 00:21:05.200 --> 00:21:09.100 from very group gray blue to darker blue. 00:21:09.100 --> 00:21:10.600 And one of the things that, 00:21:10.600 --> 00:21:15.100 you know, a lot of people notice is the cells like to hug the red blood cells. 00:21:15.100 --> 00:21:19.300 And then you have this, more intense color at the margin of the cell. 00:21:20.700 --> 00:21:23.500 Now downy, type two, 00:21:23.500 --> 00:21:26.566 reactive lymphocytes, vary in morphology there. 00:21:26.566 --> 00:21:29.233 They're still large cells. 00:21:29.233 --> 00:21:32.933 They may have nuclei and they have once again, this reactive 00:21:32.933 --> 00:21:37.833 appearing, cytoplasm with a vacuoles or sometimes, red granules. 00:21:38.133 --> 00:21:40.766 So they may look a lot like LCL. 00:21:43.333 --> 00:21:44.033 Downy type 00:21:44.033 --> 00:21:47.766 three cells or also called immune oblast like cells. 00:21:47.933 --> 00:21:51.400 Those are actually pretty scary looking if you encounter them in your practice. 00:21:51.633 --> 00:21:55.300 So those are large cells, very dark blue cytoplasm 00:21:55.666 --> 00:21:58.900 and large nucleus, usually around. 00:21:58.900 --> 00:22:01.533 Sometimes it can be irregular, as in this case. 00:22:01.533 --> 00:22:04.766 Another feature that may scare scientists 00:22:04.766 --> 00:22:07.766 is that nuclei or light, they can be quite prominent. 00:22:08.833 --> 00:22:11.800 And plasma say to a lymphocyte is another type 00:22:11.800 --> 00:22:14.933 of reactive lymphocyte that looks a lot like a plasma cell. 00:22:15.166 --> 00:22:18.233 So it's very important to actually not to confuse it with plasma cells 00:22:18.233 --> 00:22:21.166 because the clinical implications may be very different. 00:22:21.166 --> 00:22:24.166 Different. 00:22:24.700 --> 00:22:25.033 All right. 00:22:25.033 --> 00:22:28.033 So in a case like this, 00:22:29.200 --> 00:22:33.166 when we just look at morphology and recognize that there's something 00:22:33.166 --> 00:22:38.200 that is not usual with this particular smear other any other tools that, 00:22:38.333 --> 00:22:41.600 you know, I myself use and I teach my residents to use. 00:22:42.066 --> 00:22:45.466 So there are a lot of things that are available to the laboratory 00:22:45.466 --> 00:22:47.833 technicians and technologists. 00:22:47.833 --> 00:22:50.200 So first of all, we'll look at the patient's information. 00:22:50.200 --> 00:22:53.633 We'll look at the age of the patient because the conditions that are associated 00:22:53.633 --> 00:22:58.900 with abnormal lymphocytes differ from younger population, 00:22:59.533 --> 00:23:02.033 to older individuals. 00:23:02.033 --> 00:23:05.666 We'll look at the clinical information which can be very limited. 00:23:06.266 --> 00:23:09.266 Especially for the laboratory scientists. 00:23:09.366 --> 00:23:13.133 We may look at the previous laboratory results and see if, 00:23:13.633 --> 00:23:14.666 the patient has had 00:23:14.666 --> 00:23:17.733 those abnormal cells reported before and what they were called before. 00:23:18.600 --> 00:23:21.700 We can look at other results and or other orders 00:23:21.700 --> 00:23:26.400 to give us some understanding of what exactly the clinical team is looking for. 00:23:27.700 --> 00:23:28.733 Now we can turn to 00:23:28.733 --> 00:23:32.166 the CDC indices, because those can be very helpful. 00:23:32.533 --> 00:23:35.500 So we, we usually look at, does the patient 00:23:35.500 --> 00:23:38.500 have any side opinions? 00:23:38.533 --> 00:23:41.500 Is there, absolute lymphocyte ptosis? 00:23:41.500 --> 00:23:43.366 What's the degree of lymphocyte ptosis? 00:23:43.366 --> 00:23:45.266 Is there, lymphocyte apnea. 00:23:45.266 --> 00:23:48.266 So all of those things can be very, very helpful. 00:23:49.000 --> 00:23:53.466 Then looking at the slide again, I try to always answer questions. 00:23:53.466 --> 00:23:58.066 So those weird lymphocytes, do they comprise 00:23:58.766 --> 00:24:03.000 a totally, you know, different population from normal lymphocytes within that smear 00:24:03.300 --> 00:24:04.000 or you see the whole 00:24:04.000 --> 00:24:07.233 spectrum of different morphology because that could be very, very helpful. 00:24:07.800 --> 00:24:10.400 And then once again, when you actually, 00:24:10.400 --> 00:24:14.033 evaluate the cells, try to find the reference cells that you know 00:24:14.033 --> 00:24:17.200 for sure it's a normal small lymphocyte and you can go from there. 00:24:19.166 --> 00:24:19.733 So in this 00:24:19.733 --> 00:24:23.033 particular patient, I'm just going to go back to the smear. 00:24:23.033 --> 00:24:25.600 So that was from the same patient okay. 00:24:25.600 --> 00:24:28.833 There are some very ugly cells, very scary cells. 00:24:29.166 --> 00:24:31.900 But that patient did not have any side apnea. 00:24:31.900 --> 00:24:34.600 And he was an, younger individual. 00:24:34.600 --> 00:24:37.300 So in this particular context, 00:24:37.300 --> 00:24:40.333 the overall findings were consistent with viral infection. 00:24:40.333 --> 00:24:43.800 And EBV was one of those infections that we were really thinking of. 00:24:46.833 --> 00:24:48.766 So infectious mononucleosis. 00:24:48.766 --> 00:24:52.066 And as we know, it's caused by, EBV virus and, 00:24:54.033 --> 00:24:57.600 when, when the person has the primary infection, 00:24:57.600 --> 00:25:00.400 it usually is associated with lymphocyte ptosis. 00:25:00.400 --> 00:25:02.800 And in many cases the lymphocyte may have this 00:25:02.800 --> 00:25:05.900 variable morphology with a lot of scary looking forms. 00:25:06.733 --> 00:25:10.100 There are some morphology criteria that may be applied in certain cases, 00:25:10.100 --> 00:25:14.833 especially to guide the clinical team and to, kind of help them, 00:25:16.066 --> 00:25:19.066 order some tests that would be relevant. 00:25:19.100 --> 00:25:23.233 And among those criteria, we'll look at the number of lymphocytes and monocytes. 00:25:23.233 --> 00:25:28.000 And they're usually more than 50% of the white blood cells in the differential. 00:25:29.033 --> 00:25:30.933 At least 10% of the lymphocytes 00:25:30.933 --> 00:25:34.300 of the white blood cells would be reactive lymphocytes. 00:25:34.900 --> 00:25:39.366 And we also look for very significant lymphocytic heterogeneity. 00:25:39.366 --> 00:25:42.566 It would be very, very helpful as in the case I just showed you. 00:25:43.433 --> 00:25:46.466 And then if we end up running flow cytometry, 00:25:46.500 --> 00:25:49.866 which is not, you know, particularly appropriate in a case like this, 00:25:50.166 --> 00:25:53.166 then we'll see that those reactive lymphocytes would be, 00:25:53.800 --> 00:25:55.966 would be T cells 00:25:55.966 --> 00:25:58.966 that are eight positive CD4 negative. 00:26:00.766 --> 00:26:01.066 All right. 00:26:01.066 --> 00:26:03.866 So I have several cases for us to look at. 00:26:03.866 --> 00:26:08.900 And you know, learn on some morphology and some clinical, 00:26:09.900 --> 00:26:13.000 implication that, our judgment might have. 00:26:13.833 --> 00:26:16.833 So here's our first patient is a middle aged man. 00:26:17.333 --> 00:26:21.733 And the CBC showed that he has normal hemoglobin. 00:26:22.633 --> 00:26:25.600 He has slightly decreased platelets, 00:26:25.600 --> 00:26:28.600 but he has pretty high WBC count. 00:26:28.733 --> 00:26:31.733 And this is what his smear looks like. 00:26:31.800 --> 00:26:33.866 Okay, 00:26:33.866 --> 00:26:36.566 now I also took a picture of, 00:26:36.566 --> 00:26:39.400 you know, isolated cells so we can, see the lymphocyte. 00:26:39.400 --> 00:26:42.500 Well, lymphocyte, population, better. 00:26:42.500 --> 00:26:48.500 So as you see, the patient has different type of, mononuclear cells. 00:26:48.900 --> 00:26:52.366 The cytoplasm is granular and we have cells like this 00:26:52.866 --> 00:26:55.500 just, you know, basically a nucleus with a little bit of cytoplasm. 00:26:55.500 --> 00:26:58.166 You have larger cells right here. 00:26:58.166 --> 00:27:00.500 So once again I'm going to look at the CBC. 00:27:00.500 --> 00:27:00.900 Right. 00:27:00.900 --> 00:27:03.900 And I see that there is increased lymphocytes 00:27:04.600 --> 00:27:07.200 by CBC by the analyzer. 00:27:07.200 --> 00:27:08.900 This is what the case was. 00:27:08.900 --> 00:27:12.466 And then I'm going to look at I'm going to try to find the reference points. 00:27:12.466 --> 00:27:15.666 So which of those cells would definitely be considered small lymphocytes. 00:27:16.466 --> 00:27:18.433 And here they are right thinking. 00:27:18.433 --> 00:27:22.466 The smaller cells from nucleus very dark dense chromatin. 00:27:22.933 --> 00:27:26.066 Now I'm looking at the other cell population. 00:27:26.300 --> 00:27:29.300 And to my understanding, they look like 00:27:29.300 --> 00:27:32.733 a separate population of morphologically abnormal cells. 00:27:34.900 --> 00:27:35.400 Those cells are 00:27:35.400 --> 00:27:39.966 larger and they have different chromatin than those lymphocytes. 00:27:40.300 --> 00:27:43.300 So the chromatin is not particularly mature. 00:27:43.500 --> 00:27:48.033 What we see in, you know, myeloid blasts, but it's it's more homogenous. 00:27:48.033 --> 00:27:52.066 And there are some cells that kind of show nucleolus here and there. 00:27:54.100 --> 00:27:57.933 So the initial interpretation of the cells was that those were blasts. 00:27:58.200 --> 00:28:01.100 And we counted 64% of them. 00:28:01.100 --> 00:28:04.800 The flow Cytometric, evaluation that followed the peripheral blood 00:28:04.800 --> 00:28:08.800 smear evaluation showed that those cells were positive for Covid 19, 00:28:09.700 --> 00:28:12.766 weakly positive for CD 22 and positive for RT. 00:28:13.300 --> 00:28:16.133 And there was no, expression of the 20, 00:28:16.133 --> 00:28:19.133 which is expected to be seen on mature cells. 00:28:19.666 --> 00:28:23.200 So the final diagnosis was acute lymphoblastic leukemia lymphoma. 00:28:24.000 --> 00:28:24.200 Right. 00:28:24.200 --> 00:28:28.566 So this is this case illustrates, the morphology 00:28:28.566 --> 00:28:31.566 of lymphoid blast that we encounter. 00:28:32.033 --> 00:28:35.533 And once again, those cells are usually on the larger scale. 00:28:35.800 --> 00:28:39.366 But we have to be very careful with, lymphoblastic because sometimes 00:28:39.366 --> 00:28:42.366 they may look very, very similar to just mature lymphocytes. 00:28:44.033 --> 00:28:45.600 Other, 00:28:45.600 --> 00:28:48.600 features that would help us would definitely be, 00:28:48.900 --> 00:28:52.166 the nature of chromatin, which is, more immature. 00:28:52.566 --> 00:28:55.900 And you clearly, once again, they can be appreciated sometimes, 00:28:56.100 --> 00:29:00.300 but there are cases when you do not see nucleus like so you should not, count 00:29:00.300 --> 00:29:03.366 a nucleus like as your, feature 00:29:03.366 --> 00:29:06.366 for distinction. 00:29:07.566 --> 00:29:07.966 All right. 00:29:07.966 --> 00:29:12.066 There's a, second patient, 78 year old man 00:29:13.466 --> 00:29:16.466 that is, being seen for, 00:29:17.433 --> 00:29:19.066 increased WBC again. 00:29:19.066 --> 00:29:20.833 So he has 8 to 7000. 00:29:20.833 --> 00:29:24.966 WBC is hemoglobin is 12 and platelets are normal. 00:29:26.466 --> 00:29:29.000 And, on this lower magnification 00:29:29.000 --> 00:29:32.000 we do appreciate a lot of lymphoid cells. 00:29:32.200 --> 00:29:34.000 Right. 00:29:34.000 --> 00:29:36.866 Now let's look for the reference. 00:29:36.866 --> 00:29:40.933 It's really hard to appreciate it looks like all this mononuclear cells 00:29:40.933 --> 00:29:43.933 kind of have very similar look to them. 00:29:45.966 --> 00:29:49.600 And on higher power those cells do resemble lymphocytes right. 00:29:49.600 --> 00:29:51.633 In fact they might be lymphocytes. 00:29:51.633 --> 00:29:54.700 They're smaller. They have very dense 00:29:55.900 --> 00:29:56.500 chromatin. 00:29:56.500 --> 00:29:58.000 They have very little cytoplasm. 00:29:58.000 --> 00:30:00.633 It has no granules. 00:30:00.633 --> 00:30:04.000 So the laboratory call those cells abnormal lymphocytes. 00:30:04.300 --> 00:30:07.100 And once again the flow cytometry was performed. 00:30:07.100 --> 00:30:10.600 And those cells were B-cells that were expressing CS 19. 00:30:10.600 --> 00:30:13.600 And they also received 20 positive 00:30:14.233 --> 00:30:18.400 and overall flow cytometry findings were consistent 00:30:18.400 --> 00:30:21.900 with chronic lymphocytic leukemia small lymphocytic lymphoma. 00:30:22.000 --> 00:30:25.000 So the patient was diagnosed with Class-A. 00:30:25.300 --> 00:30:28.300 And this is what the classic classical cells would look like. 00:30:28.733 --> 00:30:31.666 They're usually smaller lymphocytes. 00:30:31.666 --> 00:30:35.400 They have a lot of features of just mature B cells. 00:30:35.466 --> 00:30:35.800 Right. 00:30:35.800 --> 00:30:39.933 So a high end C ratio, very scant cytoplasm with no granules. 00:30:40.166 --> 00:30:44.566 And the chromatin is also dense, in many cases you will appreciate that, 00:30:44.800 --> 00:30:48.366 it has this cracked appearance that sometimes is compared 00:30:48.366 --> 00:30:52.100 to the, soccer ball in this particular cell. 00:30:53.166 --> 00:30:54.100 This nucleus actually 00:30:54.100 --> 00:30:57.100 looks a lot like soccer ball. 00:30:58.600 --> 00:31:01.133 So it still is a very common, 00:31:01.133 --> 00:31:05.066 B-cell lymphoma proliferative disorder, especially in the elderly population. 00:31:05.766 --> 00:31:09.900 And, in this neoplasm, there is accumulation 00:31:09.900 --> 00:31:14.833 of the clonal, B-cells that have a very characteristic immuno phenotype. 00:31:15.100 --> 00:31:16.933 They are positive for 19. 00:31:16.933 --> 00:31:18.733 They express it in 20, 00:31:18.733 --> 00:31:21.866 at a lower level than we would expect in the mature lymphocyte. 00:31:22.333 --> 00:31:27.133 They also have monoclonal expression of light chains at the lower level. 00:31:27.533 --> 00:31:30.300 And they are positive for C5. 00:31:30.300 --> 00:31:34.433 Other markers that we use here would be 23 of 200, 00:31:34.433 --> 00:31:37.500 which are really helpful in certain clinical settings. 00:31:37.866 --> 00:31:40.600 And other markers that we can use, 00:31:40.600 --> 00:31:43.733 especially in immunohistochemistry, there would be less one 00:31:43.733 --> 00:31:47.833 which is positive in CL and cyclin D one is expected to be negative. 00:31:50.566 --> 00:31:51.133 If we talk 00:31:51.133 --> 00:31:55.100 about CLL, we also need to mention a monoclonal 00:31:55.100 --> 00:31:59.333 B-cell lymphocyte ptosis, which is a, newer entity. 00:31:59.866 --> 00:32:02.866 And it is 00:32:03.133 --> 00:32:07.000 defined as circulating monoclonal B-cells, 00:32:07.333 --> 00:32:10.366 but their number should be less than 5000 per microliter 00:32:10.900 --> 00:32:14.933 there should be no other clinical symptoms that would suggest, lymphoid, 00:32:14.933 --> 00:32:18.400 proliferative, that would suggest a full blown lymphoma such as organo 00:32:19.133 --> 00:32:22.133 lymphadenopathy or sided PDL. 00:32:22.700 --> 00:32:24.400 So the morphologically, 00:32:24.400 --> 00:32:29.266 those monoclonal B-cells are usually similar to what we see in CLL. 00:32:29.500 --> 00:32:32.500 Once again, the difference is the number in CLL. 00:32:32.500 --> 00:32:36.033 We see, those cells over 5000 per microliter. 00:32:36.200 --> 00:32:39.200 And in a monoclonal B-cell lymphocyte doses would be less. 00:32:39.966 --> 00:32:42.966 Now if we, just look at all those cases 00:32:42.966 --> 00:32:46.633 with MVL, the immuno phenotype may be different. 00:32:46.633 --> 00:32:50.200 And, those samples will be divided into three main categories. 00:32:50.700 --> 00:32:53.866 So the most common category is cluster phenotype. 00:32:54.266 --> 00:32:57.700 So by flow those monoclonal B cells are going to be, 00:32:58.000 --> 00:33:02.400 you know, with that Cd28 expression light chain DM and 23 positive. 00:33:03.866 --> 00:33:04.933 Less commonly we would 00:33:04.933 --> 00:33:08.300 encounter what we call a typical CML immune phenotype. 00:33:08.700 --> 00:33:12.400 When the CD 20 expression is at a higher level than expected, 00:33:12.766 --> 00:33:16.366 and when the light chains are also on the moderate to bright side. 00:33:16.633 --> 00:33:21.333 And in those cases, T to 23 can also be either weakly positive or even negative, 00:33:22.300 --> 00:33:26.633 and the least common type of b l would be non-self phenotype 00:33:27.100 --> 00:33:30.100 with the B cells being negative for CD five. 00:33:30.700 --> 00:33:33.200 Now, from the clinical perspective, it's also important 00:33:33.200 --> 00:33:36.333 to separate symbols into low 00:33:36.333 --> 00:33:41.166 count symbols where the monoclonal cells are less than 0.5 thousand 00:33:41.500 --> 00:33:44.500 and those that have higher, counts. 00:33:44.500 --> 00:33:46.966 And it has been shown that, those symbols 00:33:46.966 --> 00:33:50.100 with higher counts are more likely to progress into full blown, 00:33:50.600 --> 00:33:54.000 leukemia lymphoma at the rate of about 1 to 2% per year. 00:33:56.166 --> 00:33:56.533 Okay. 00:33:56.533 --> 00:33:59.333 Next patient, 00:33:59.333 --> 00:34:01.000 6070 year old woman. 00:34:01.000 --> 00:34:04.066 And she is also being seen for a very high WBC 00:34:04.066 --> 00:34:07.233 count, as you see, over 5000 500,000. 00:34:07.900 --> 00:34:10.900 She also has anemia and she has thrombocytopenia. 00:34:11.066 --> 00:34:13.800 And this is what her senior looks like 00:34:13.800 --> 00:34:17.266 a lot of very monotonously appearing lymphoid cells. 00:34:17.266 --> 00:34:19.800 Right. 00:34:19.800 --> 00:34:22.333 On higher magnification 00:34:22.333 --> 00:34:25.200 we see that those cells have lymphoid 00:34:25.200 --> 00:34:28.800 appearance with more abundant cytoplasm than this holding cell site. 00:34:29.100 --> 00:34:30.666 They're obviously larger. 00:34:30.666 --> 00:34:35.866 And what makes, this case unique is that almost every lymphoid cell has 00:34:35.866 --> 00:34:38.866 a very prominent nucleolus, mostly one, 00:34:39.333 --> 00:34:42.033 but some cells have to see that. 00:34:42.033 --> 00:34:44.566 So, the laboratory, 00:34:44.566 --> 00:34:47.166 step classify those cells as abnormal lymphocytes. 00:34:47.166 --> 00:34:50.166 And there is a subcategory that we call for lymphocytes. 00:34:50.366 --> 00:34:55.000 So this patient had 97% for lymphocytes in the peripheral blood. 00:34:55.533 --> 00:34:58.100 And once again the flow cytometry did confirm 00:34:58.100 --> 00:35:01.100 that those cells were of B cell in each. 00:35:01.533 --> 00:35:05.833 And the final diagnosis for this patient was B April lymphocytic leukemia. 00:35:06.866 --> 00:35:07.633 So the problem for 00:35:07.633 --> 00:35:10.700 site is a morphologic term right. 00:35:10.700 --> 00:35:13.900 If you kind of hear into it, you think that, you know, probably 00:35:14.133 --> 00:35:16.366 it would be a more immature cell than the lymphocyte. 00:35:16.366 --> 00:35:18.400 But that's not that's not the case. 00:35:18.400 --> 00:35:21.800 And all the, all the time, morphologically 00:35:21.800 --> 00:35:24.800 for lymphocytes are larger than small lymphocytes. 00:35:25.266 --> 00:35:28.500 They have NC ratios slightly, lower. 00:35:29.566 --> 00:35:34.766 And the most important feature is to identify a large prominent nucleolus. 00:35:34.766 --> 00:35:37.433 And the clueless is usually centrally located. 00:35:37.433 --> 00:35:40.433 But it can be centric as well. 00:35:42.066 --> 00:35:44.866 So when we see lymphocytes in the peripheral blood, 00:35:44.866 --> 00:35:48.466 there are several, clinical scenarios that can give us that finding. 00:35:49.600 --> 00:35:51.833 So one of them would be a mature 00:35:51.833 --> 00:35:54.833 B-cell lymphoma such as CLL. 00:35:55.000 --> 00:35:58.600 So if you have a case of C and if you take your time 00:35:58.600 --> 00:36:02.533 and look at those yellow, cells, a lot of cases will actually show 00:36:02.533 --> 00:36:06.666 a smaller proportion of cells with lymphocytic morphology. 00:36:07.000 --> 00:36:10.366 And that, particular finding does not have clinical implications. 00:36:11.800 --> 00:36:13.900 Sometimes, there is a pretty 00:36:13.900 --> 00:36:17.766 prominent population of lymphocytes in the context of CLL. 00:36:18.166 --> 00:36:21.233 And those cases sometimes are called atypical CLO. 00:36:22.000 --> 00:36:26.266 And this abnormal morphology is commonly associated with them at 12. 00:36:26.266 --> 00:36:31.500 And sometimes by flow cytometry will also be, able to see some abnormal phenotype. 00:36:32.466 --> 00:36:35.433 Now there's another category 00:36:35.433 --> 00:36:39.200 is what we call pro lymphocyte transformation. 00:36:39.600 --> 00:36:42.233 When the CL progresses 00:36:42.233 --> 00:36:45.866 into this more morphologically aggressive and clinically aggressive form. 00:36:46.266 --> 00:36:50.266 But in that particular case, the phenotype will usually be retained. 00:36:50.266 --> 00:36:53.266 And it would be consistent with CML. 00:36:54.233 --> 00:36:56.333 Another neoplasm 00:36:56.333 --> 00:36:59.800 that lymphocyte can be seen in would be mantle cell lymphoma. 00:37:00.300 --> 00:37:02.200 Right. So this is another thing we need to remember. 00:37:02.200 --> 00:37:05.400 And we'll go back to this, to mental cell lymphoma a little bit later. 00:37:06.400 --> 00:37:07.166 Okay. 00:37:07.166 --> 00:37:11.400 B for lymphocytic leukemia, this is another entity that by definition, 00:37:11.400 --> 00:37:16.000 should, show more than 55%, probing for sight in the peripheral blood. 00:37:16.333 --> 00:37:19.966 And it's very important to understand that problem B, problem specific 00:37:19.966 --> 00:37:23.200 leukemia does not have anything to do with CL. 00:37:23.900 --> 00:37:24.133 Okay. 00:37:25.100 --> 00:37:26.800 It's a rare disease. 00:37:26.800 --> 00:37:29.933 And, it usually precludes very poor prognosis 00:37:31.400 --> 00:37:33.500 now T for lymphocytic leukemia. 00:37:33.500 --> 00:37:36.366 So once again morphologically we see Pro lymphocytes. 00:37:36.366 --> 00:37:39.400 And they would be of telling H that they would express you three. 00:37:40.366 --> 00:37:44.366 And it's another rare disease in this very highly aggressive disease. 00:37:45.166 --> 00:37:48.700 So in those cases the morphology can be very helpful 00:37:49.100 --> 00:37:52.600 because if you compare the T Pro lymphocytes versus 00:37:52.600 --> 00:37:55.600 B Pro lymphocytes in the B Pro lymphocytic leukemia, 00:37:55.700 --> 00:37:59.200 you might notice that the nucleus is definitely more irregular. 00:37:59.800 --> 00:38:02.133 The chromatin can be a little bit denser. 00:38:02.133 --> 00:38:05.900 The nucleolus can not be as prominent as in B Pro lymphocytes. 00:38:06.233 --> 00:38:09.300 And another feature to look for is those cytoplasmic blobs. 00:38:10.500 --> 00:38:12.833 So once again this is a very aggressive 00:38:12.833 --> 00:38:15.833 disease with poor prognostic prognosis. 00:38:16.066 --> 00:38:20.766 And by flow cytometry in in a significant 00:38:21.100 --> 00:38:24.766 subset of those cases, we'll see double expression of CD4 and CD8. 00:38:28.833 --> 00:38:29.100 All right. 00:38:29.100 --> 00:38:30.300 Next patient. 00:38:30.300 --> 00:38:34.500 So we have elderly men with mild anemia 00:38:34.666 --> 00:38:38.600 thrombocytopenia and normal WBC count. 00:38:38.966 --> 00:38:41.966 And now here I also put the differential. 00:38:41.966 --> 00:38:45.700 And in the differential you'll notice that there's no monocytes. 00:38:45.966 --> 00:38:48.966 So that could be a clue in this particular case. 00:38:49.033 --> 00:38:52.033 So if we look closer those lymphocytes 00:38:52.266 --> 00:38:56.100 they also do not look normal right round or oval nuclei. 00:38:56.700 --> 00:38:59.766 Larger if you compare them to the red blood cells. 00:38:59.766 --> 00:39:03.233 But I hope all of you have noticed those protrusions. 00:39:05.300 --> 00:39:08.000 So, those cells were interpreted as hairy cells. 00:39:08.000 --> 00:39:11.866 And once again, the flow cytometry did show that those cells were of 00:39:11.900 --> 00:39:13.266 gasoline each. 00:39:13.266 --> 00:39:17.033 But they had unusual set of markers expressed among those, 00:39:17.666 --> 00:39:22.633 were CD1 one of three, C, D, 25, 11 C, and 123. 00:39:22.866 --> 00:39:27.600 We also noticed that both C20 and light chains were very brightly expressed. 00:39:27.866 --> 00:39:31.600 So all those findings were consistent with here is cell leukemia. 00:39:32.800 --> 00:39:33.266 So here is 00:39:33.266 --> 00:39:37.033 cell leukemia is it's not a very common neoplasm. 00:39:37.033 --> 00:39:40.300 But the morphology of the cells, is very helpful. 00:39:40.900 --> 00:39:43.033 So those are usually larger cells. 00:39:43.033 --> 00:39:45.866 And they have around two oval nuclei 00:39:45.866 --> 00:39:49.533 with kind of more homogenous but still mature chromatin. 00:39:50.033 --> 00:39:51.833 The nuclei are absent. 00:39:51.833 --> 00:39:54.700 And once again, we're looking for, 00:39:54.700 --> 00:39:58.900 those extension of the cytoplasm, this frayed look of those cells. 00:39:59.366 --> 00:40:03.600 So the problem is that if you actually look at a lot of your smears 00:40:03.800 --> 00:40:07.366 at higher magnification for a long enough time, you'll always 00:40:07.366 --> 00:40:11.000 find a lymphocyte with this kind of irregularity of the cytoplasm. 00:40:11.333 --> 00:40:15.266 So it could be just, a lot of it is actually artifactual. 00:40:15.500 --> 00:40:19.600 So we need to be very, very careful, with calling lymphocytes here is cells. 00:40:20.000 --> 00:40:22.700 In fact, the IX, h 00:40:22.700 --> 00:40:25.733 group proposes those lymphocytes to be reported 00:40:25.733 --> 00:40:28.900 as abnormal lymphocytes at the first encounter. 00:40:29.166 --> 00:40:32.800 And then when those, lymphocytes are confirmed to be here or cells 00:40:32.800 --> 00:40:37.566 by a flow cytometry, the rubric can be switching to here itself. 00:40:42.400 --> 00:40:44.700 One, you know, if there's one thing to remember 00:40:44.700 --> 00:40:48.233 about here is cell leukemia, is, is that it affects, 00:40:50.400 --> 00:40:51.600 kind of more, 00:40:51.600 --> 00:40:54.600 middle age to elderly, people, mostly men. 00:40:54.900 --> 00:40:57.900 And it's associated with monocyte apnea. 00:40:58.066 --> 00:41:02.400 So if there is a question about, here is the leukemia in a particular patient, 00:41:02.400 --> 00:41:05.800 what I'm looking for is does this patient have monocyte apnea? 00:41:06.100 --> 00:41:09.100 Because if it doesn't, I really need to think twice about it. 00:41:10.900 --> 00:41:12.500 Next to here to cell leukemia. 00:41:12.500 --> 00:41:15.500 There's also here is cell leukemia a variance. 00:41:15.500 --> 00:41:17.366 Right. It's a little distractor. 00:41:17.366 --> 00:41:20.366 So those are 00:41:20.466 --> 00:41:23.733 this is the lymphoid proliferative neoplasm that can have 00:41:24.266 --> 00:41:29.666 either, varying morphology or abnormal, you know, unexpected immune phenotype. 00:41:30.366 --> 00:41:34.500 Or also a lack of B RAF, mutation. 00:41:34.766 --> 00:41:38.233 So, those cases, it's very important to actually separate 00:41:38.233 --> 00:41:40.966 those cases from really true classic areas. 00:41:40.966 --> 00:41:44.366 So, leukemia, because it represents a different entity. 00:41:44.366 --> 00:41:48.400 And the treatment for those cases, for those, patients would be different. 00:41:50.300 --> 00:41:50.633 Okay. 00:41:50.633 --> 00:41:53.000 Next patient, 00:41:53.000 --> 00:41:55.433 here we have a 60, 70 year old woman 00:41:55.433 --> 00:42:01.000 with, thrombocytopenia, with anemia and with slightly increased, 00:42:01.533 --> 00:42:04.533 number of, leukocytes. 00:42:07.400 --> 00:42:09.400 So that was a really good case because, 00:42:09.400 --> 00:42:11.700 you know, for pathologists, for the morphologies perspective, 00:42:11.700 --> 00:42:14.800 of course, because it did not take me long to find cells like this. 00:42:17.700 --> 00:42:19.900 And you might say, oh, I know what that is. 00:42:19.900 --> 00:42:21.333 We read about this in the book. 00:42:21.333 --> 00:42:24.100 They're called flower cells of the red cells. 00:42:24.100 --> 00:42:27.033 And this is what they were called initially. 00:42:27.033 --> 00:42:29.400 So this patient was, ultimately 00:42:29.400 --> 00:42:32.466 diagnosed with adult T-cell leukemia lymphoma. 00:42:33.533 --> 00:42:37.000 And, the morphology of the cells is quite unique, isn't it? 00:42:37.633 --> 00:42:40.233 So we see larger lymphocytes 00:42:40.233 --> 00:42:44.800 with very irregular nuclei, a lot of lymphocytes, but not necessarily 00:42:44.800 --> 00:42:49.933 all the time will show this appearance of a cloverleaf or a flower. 00:42:49.933 --> 00:42:51.966 That's what they that's why they call for red cells. 00:42:53.300 --> 00:42:55.700 And the chromatin in those cells will be mature. 00:42:55.700 --> 00:42:58.833 And you clearly can be present, but usually they're absent. 00:43:01.266 --> 00:43:05.300 So ATL is a very rare type of, 00:43:05.966 --> 00:43:08.966 leukemia lymphoma in the Western world 00:43:09.200 --> 00:43:12.133 because, it is caused by Htlv 00:43:12.133 --> 00:43:15.533 one virus, which is more prominent in the Caribbean or Japan. 00:43:16.266 --> 00:43:18.966 And so it takes, patient 00:43:18.966 --> 00:43:21.800 years in years between the infection 00:43:21.800 --> 00:43:25.766 and actually development of leukemia lymphoma, usually 20, 30 years. 00:43:25.766 --> 00:43:30.700 So that's why we see this entity usually in aged, individuals 00:43:32.133 --> 00:43:34.600 so immune if in a typically those cells are going 00:43:34.600 --> 00:43:37.600 to be immature T cells that express these three. 00:43:37.966 --> 00:43:40.300 Usually they're CD4 positive 00:43:40.300 --> 00:43:43.300 and they express 25 very brightly. 00:43:44.000 --> 00:43:45.666 So if we have a patient 00:43:45.666 --> 00:43:48.900 like this with a lot of, atypical lymphocytes 00:43:48.900 --> 00:43:53.133 in the peripheral blood, unfortunately those patients have, poor prognosis. 00:43:55.533 --> 00:43:55.733 Right. 00:43:55.733 --> 00:43:56.800 Next case. 00:43:56.800 --> 00:44:00.900 So here we have an elderly man with, mild thrombocytopenia, 00:44:00.900 --> 00:44:03.900 with mild anemia and with slightly increased, 00:44:04.533 --> 00:44:07.533 leukocytes. 00:44:08.000 --> 00:44:09.733 All right, 00:44:09.733 --> 00:44:11.233 so here's the problem. 00:44:11.233 --> 00:44:14.400 You know, I might look at it and I might think, oh, 00:44:14.666 --> 00:44:17.566 you know, those kind of look like monocytes in many ways. 00:44:17.566 --> 00:44:18.166 Right. 00:44:18.166 --> 00:44:23.333 So there's one of the lookalikes here, actually, unlike monocytes, those cells 00:44:23.333 --> 00:44:28.033 have more, dense chromatin as opposed to reticulated chromatin in monocytes. 00:44:28.366 --> 00:44:33.266 And as you see, the NC ratio is definitely lower than in, monocyte. 00:44:33.733 --> 00:44:39.066 But what makes it look more acidic is the nucleus, particularly how it's folded. 00:44:39.066 --> 00:44:39.466 Right. 00:44:39.466 --> 00:44:44.166 It's a very delicate nucleus, very thin nuclear membrane. 00:44:44.166 --> 00:44:45.700 And then you have this folding. 00:44:45.700 --> 00:44:50.000 And sometimes you see cells that kind of resemble the brain. 00:44:50.266 --> 00:44:53.266 Right. So we call them before nuclei. 00:44:53.733 --> 00:44:55.433 And if we see that kind of cells. 00:44:55.433 --> 00:44:58.300 So we should think about scissoring syndrome. 00:44:58.300 --> 00:45:02.600 And in this case those cells results were recognized. 00:45:03.100 --> 00:45:06.133 And the patient indeed had sensory syndrome. 00:45:09.400 --> 00:45:12.500 So sensory syndrome is also a rare entity. 00:45:12.500 --> 00:45:16.066 And it's usually, you know, if you look at the clinical history, 00:45:16.333 --> 00:45:20.200 it will be, related to, Microsoft languages. 00:45:20.733 --> 00:45:25.466 But unlike Microsoft, surgery syndrome requires diffuse with the dermis. 00:45:25.466 --> 00:45:28.366 So the patient's skin gets red throughout. 00:45:28.366 --> 00:45:31.366 They have enlarged lymph nodes throughout their body, 00:45:31.500 --> 00:45:34.300 and they have the sensory cells in the peripheral blood. 00:45:34.300 --> 00:45:39.133 It's very important also to realize that we need to count those up as a result 00:45:39.166 --> 00:45:42.966 because, one one of the criteria is, 00:45:43.733 --> 00:45:46.733 the absolute cancer, the sensory cells 00:45:47.600 --> 00:45:49.000 and sensory syndrome is also, 00:45:49.000 --> 00:45:52.000 unfortunately, an aggressive disease. 00:45:52.600 --> 00:45:55.300 The next patient is also an elderly man. 00:45:55.300 --> 00:45:59.100 And he, shows, you know, normal platelet number. 00:45:59.866 --> 00:46:03.166 Increased, leukocytes and normal human globin. 00:46:05.200 --> 00:46:06.400 Those are kind of lymphocytes. 00:46:06.400 --> 00:46:09.200 The sign is in his peripheral blood. There are smaller. 00:46:10.200 --> 00:46:12.466 But as you see, a lot of those cells 00:46:12.466 --> 00:46:16.300 have very bizarre nuclei in the way that they're kind of folded 00:46:16.733 --> 00:46:20.566 and have this little crack statistical buttocks, buttocks cell. 00:46:20.566 --> 00:46:23.600 So here I had to be very careful, posting the picture 00:46:25.300 --> 00:46:27.600 and so, 00:46:27.600 --> 00:46:31.300 in this particular case, those, B cells expressed to the ten 00:46:31.933 --> 00:46:36.233 and, the, ultimate diagnosis was rendered follicular lymphoma. 00:46:37.166 --> 00:46:38.666 So by themselves, you know, as these 00:46:38.666 --> 00:46:41.200 if you remember the name, you'll probably remember the morphology. 00:46:41.200 --> 00:46:44.200 Right. So this is the left nucleus. 00:46:44.333 --> 00:46:48.066 Sometimes you see more convoluted, more kind of folded nuclei. 00:46:48.400 --> 00:46:50.600 And the chromatin is also quite maturing. 00:46:50.600 --> 00:46:53.100 Dense. 00:46:53.100 --> 00:46:55.666 So those cells can be seen in follicular lymphoma. 00:46:55.666 --> 00:46:58.100 I mean this particular case was follicular lymphoma. 00:46:58.100 --> 00:47:01.000 However this morphology is not, 00:47:01.000 --> 00:47:03.300 specific for, for this entity. 00:47:03.300 --> 00:47:05.666 So follicular lymphoma is a very common disease. 00:47:05.666 --> 00:47:11.466 And the cells the neoplastic cells have this germinal center phenotype. 00:47:11.466 --> 00:47:16.033 And they express obviously B cell markers plus Q10 and BCL six. 00:47:17.800 --> 00:47:18.266 All right. 00:47:18.266 --> 00:47:21.833 What if I showed you this case with those cells. 00:47:22.100 --> 00:47:25.100 But I told you that this came from a young boy, 00:47:26.233 --> 00:47:26.600 right. 00:47:26.600 --> 00:47:31.033 So, we we see follicular lymphoma, you know, the classic 00:47:31.033 --> 00:47:35.400 follicular lymphoma in kind of more, mature population. 00:47:35.400 --> 00:47:36.400 But here we have a boy. 00:47:36.400 --> 00:47:39.200 What you would do with this. 00:47:39.200 --> 00:47:42.533 So very similar morphology can be seen in whooping cough, 00:47:43.033 --> 00:47:46.766 a disease that you do not hear that often anymore, thank goodness. 00:47:46.900 --> 00:47:48.200 But it still happens. 00:47:48.200 --> 00:47:51.200 So this disease is caused by Bordetella pertussis. 00:47:51.400 --> 00:47:54.900 And you know, you've probably noticed that as we talked about lymphocytes 00:47:55.000 --> 00:47:56.166 we always had viral. 00:47:56.166 --> 00:48:00.033 This is EBV same V all these things because the bacterial infection 00:48:00.033 --> 00:48:04.300 usually does not we usually do not have caused lymphocyte ptosis. 00:48:04.500 --> 00:48:07.533 So whooping cough is a really good, exception to this rule. 00:48:08.000 --> 00:48:10.200 And especially in kids the lymphocyte. 00:48:10.200 --> 00:48:10.666 Lymphocyte. 00:48:10.666 --> 00:48:12.100 So this can be very striking 00:48:12.100 --> 00:48:15.100 because the toxin that is secreted by that, but by that 00:48:15.100 --> 00:48:19.300 microorganism prevents B-cells from actually getting into the lymph node. 00:48:19.600 --> 00:48:21.433 So they just circulate in the blood. 00:48:21.433 --> 00:48:23.100 And, you know, just hanging out there. 00:48:24.533 --> 00:48:26.800 Anyway, so 00:48:26.800 --> 00:48:29.666 sometimes in kids with whooping cough, we may see 00:48:29.666 --> 00:48:31.666 lots of lymphocytes as in this case. 00:48:31.666 --> 00:48:34.600 And a lot of those lymphocytes will look, 00:48:34.600 --> 00:48:37.400 you know, as those buttock cells. 00:48:37.400 --> 00:48:40.000 So we have to be careful there okay. 00:48:40.000 --> 00:48:41.266 Another case. 00:48:41.266 --> 00:48:45.533 So this patient showed a very large population of lymphocytes like this. 00:48:46.000 --> 00:48:48.800 And you know looking at well I know those are lymphocytes. 00:48:48.800 --> 00:48:52.266 But if you look at the smear first time you may not be sure 00:48:52.266 --> 00:48:53.933 that those are lymphocytes. Right. 00:48:53.933 --> 00:48:57.733 So humongous cells with very kind of large nuclei and 00:48:58.033 --> 00:49:01.300 and the more immature type of chromatin sometimes nuclei. 00:49:02.366 --> 00:49:05.366 So this patient unfortunately had Burkitt lymphoma. 00:49:06.100 --> 00:49:08.333 It's it's a very aggressive B-cell 00:49:08.333 --> 00:49:11.333 neoplasm that 00:49:11.700 --> 00:49:14.200 can affect, you know, different parts of your body. 00:49:14.200 --> 00:49:18.166 And sometimes those cells go to the, bone marrow and into the full blood. 00:49:18.766 --> 00:49:23.266 So the Burkitt lymphoma cells have this very ugly appearance. 00:49:24.366 --> 00:49:25.133 If you look from 00:49:25.133 --> 00:49:28.133 case to case, it can be a large medium size. 00:49:28.133 --> 00:49:31.733 Sometimes they can be smaller, but if you see at the cell population 00:49:31.733 --> 00:49:35.933 within the same case, you'll be surprised how similar the cells will look like. 00:49:35.933 --> 00:49:38.066 In this particular case. 00:49:38.066 --> 00:49:39.700 And as you see, those are large cells. 00:49:39.700 --> 00:49:44.133 And one of the things that, might be helpful, but not obviously not 00:49:44.266 --> 00:49:47.500 specific, is the evacuation of the cytoplasm. 00:49:47.766 --> 00:49:50.766 And also, see how blue the cytoplasm is? 00:49:54.466 --> 00:49:54.966 All right. 00:49:54.966 --> 00:49:57.300 And now we have a mimic or a wall here. 00:49:57.300 --> 00:49:59.366 I have two different patients. 00:49:59.366 --> 00:50:01.600 That was patient one 00:50:01.600 --> 00:50:03.500 that showed 00:50:03.500 --> 00:50:06.400 a whole bunch of very large and ugly cells. 00:50:06.400 --> 00:50:07.766 Right. So we'll look at those. 00:50:07.766 --> 00:50:10.166 And we know those are abnormal cells. 00:50:10.166 --> 00:50:14.400 Patient two the cells were also abnormal but not to that degree. 00:50:16.000 --> 00:50:16.833 So both of those 00:50:16.833 --> 00:50:19.833 patients actually had mantle cell lymphoma. 00:50:20.966 --> 00:50:23.100 You know, it's a very, 00:50:23.100 --> 00:50:26.100 aggressive neoplasm of mature B cells. 00:50:26.300 --> 00:50:31.333 And, sometimes we see the lymphoma cells in the peripheral blood, and, 00:50:31.500 --> 00:50:34.433 they are morphology can be quite variable, which makes it, you 00:50:34.433 --> 00:50:37.433 know, you have you have to always remember about this entity. 00:50:37.933 --> 00:50:40.300 Sometimes they look like CLL cells. 00:50:40.300 --> 00:50:43.633 And, this would happens in so-called small cell variant. 00:50:43.933 --> 00:50:47.200 And sometimes it can look like glass, you know, and you look at this image 00:50:47.200 --> 00:50:48.933 and, you know, there's a blast. 00:50:48.933 --> 00:50:52.533 But then the flow comes back and, you know, those are mature B cells 00:50:52.533 --> 00:50:55.533 with, expression CD five. 00:50:56.866 --> 00:50:57.400 All right. 00:50:57.400 --> 00:51:00.566 And, one more thing that we have not talked about 00:51:00.566 --> 00:51:03.566 would be a plasma cells. 00:51:05.000 --> 00:51:08.100 So plasma cells, we've talked about plasma cells with lymphocytes. 00:51:08.100 --> 00:51:10.333 We could be a mimic of plasma cells. 00:51:10.333 --> 00:51:13.833 So the plasma cells in the classic plasma cell is intermediate 00:51:13.833 --> 00:51:16.800 to larger cell with round, very round nucleus. 00:51:16.800 --> 00:51:20.700 When especially when we talk about mature plasma cells, the nuclei, 00:51:20.800 --> 00:51:23.600 they should not be there. And the chromatin is very dense. 00:51:23.600 --> 00:51:28.400 And sometimes, you see cells with so-called clock pattern of chromatin. 00:51:29.033 --> 00:51:33.633 The cytoplasm is usually dark blue with some period nuclear clearing. 00:51:34.033 --> 00:51:38.200 And, in some cells you may see that there's kind of a round area. 00:51:38.200 --> 00:51:39.766 We call it huff. 00:51:39.766 --> 00:51:42.666 Sometimes vacuoles can be also appreciated. 00:51:42.666 --> 00:51:46.100 So there are a few of lookalikes to the cells. 00:51:46.466 --> 00:51:48.133 Always need to be careful about that. 00:51:48.133 --> 00:51:50.666 One of those would be nucleated red blood cell. 00:51:50.666 --> 00:51:54.333 You know in this particular case you look at the red blood cell 00:51:54.333 --> 00:51:58.733 and you tell that, you know, this cell is definitely smaller than the lymphocyte, 00:51:58.866 --> 00:52:00.166 then the plasma cells should be. 00:52:00.166 --> 00:52:03.900 So in this case it was not very difficult to distinguish. 00:52:04.166 --> 00:52:05.200 But there are smears. 00:52:05.200 --> 00:52:09.333 And it it takes you, you know, a minute or two to realize 00:52:09.333 --> 00:52:12.333 that those are most likely nucleated red blood cells. 00:52:12.600 --> 00:52:16.966 So plasma cells are very rarely seen in the peripheral blood. 00:52:17.300 --> 00:52:18.666 Almost never seen. And actually, 00:52:20.800 --> 00:52:23.766 in healthy individuals, however, 00:52:23.766 --> 00:52:26.166 we can see plasma cells in, 00:52:26.166 --> 00:52:31.600 reactive processes, especially when, there is autoimmune, 00:52:32.200 --> 00:52:36.266 conditions like, Artemia hepatitis or, lupus. 00:52:37.466 --> 00:52:40.566 Sometimes drug reactions and a viral infection 00:52:40.566 --> 00:52:44.966 can also, lead those plasma cells, into the circulation. 00:52:45.566 --> 00:52:49.000 But, clinically important conditions 00:52:49.000 --> 00:52:53.066 would be obvious in your plasma neoplasms, especially plasma cell neoplasms. 00:52:53.966 --> 00:52:57.100 And, one of those, we know is plasma cell leukemia. 00:52:58.300 --> 00:53:00.400 We call it because, the, 00:53:00.400 --> 00:53:03.466 plasma cells are circulating in the blood in pretty high numbers. 00:53:03.766 --> 00:53:09.100 It's usually 20% of your more than 20% of your, differential account. 00:53:09.300 --> 00:53:12.233 Or it could be more than 2000 per microliter. 00:53:12.233 --> 00:53:14.900 And, looking back at the history of this patient, 00:53:14.900 --> 00:53:18.066 we see that sometimes the plasma cells go out of the bone marrow 00:53:18.066 --> 00:53:21.300 as a consequence of a plasma cell myeloma. 00:53:21.533 --> 00:53:24.866 And this is what we call secondary, plasma cell leukemia. 00:53:25.166 --> 00:53:29.733 But in some patients, they, you know, they present with this kind of picture. 00:53:30.100 --> 00:53:33.700 And if you look at those by flow cytometry, interestingly enough, 00:53:34.066 --> 00:53:38.533 a lot of those cases will express a 20, which is not, usually expressed. 00:53:38.533 --> 00:53:41.200 It's not expressed on the, normal plasma cells. 00:53:41.200 --> 00:53:44.233 And it's not usually expressed on the multiple myeloma cases as well. 00:53:46.633 --> 00:53:47.033 All right. 00:53:47.033 --> 00:53:49.933 Well, thank you so much for, 00:53:49.933 --> 00:53:53.200 going with me through all this, a list of, of lymphocytes. 00:53:53.200 --> 00:53:57.100 And, here are some of those examples we went through. 00:53:57.100 --> 00:54:01.066 And once again, you see that the lymphocytes can be very, very tricky. 00:54:01.066 --> 00:54:04.066 They can look very similar to normal and abnormal or can 00:54:04.366 --> 00:54:06.266 they can look very different. 00:54:06.266 --> 00:54:10.000 So but there are several key points I would like to take with you. 00:54:10.533 --> 00:54:15.000 So one of them is that the morphology is a very important, 00:54:15.633 --> 00:54:19.400 way to evaluate specimens, to evaluate the result blood. 00:54:19.766 --> 00:54:26.300 And in many cases, morphology is the gatekeeper for additional, studies. 00:54:26.300 --> 00:54:30.100 And also a very, important tool that will, 00:54:30.700 --> 00:54:33.333 guide the clinicians. 00:54:33.333 --> 00:54:37.466 The morphological findings themselves may not be specific. 00:54:37.466 --> 00:54:39.566 And in a lot of cases they're not specific. 00:54:39.566 --> 00:54:43.766 Therefore they have to be put into right clinical context and interpreted properly. 00:54:44.466 --> 00:54:48.266 And with that said, the teamwork between the clinical team, 00:54:48.500 --> 00:54:51.700 between the laboratory professionals and the pathologist is a key. 00:54:53.800 --> 00:54:56.433 So thank you so much for your attention and for being here. 00:54:56.433 --> 00:54:58.966 And I'm open to questions. Thanks.