And thank you so much. Thank you very much for giving me this opportunity. And it's more like a class that I take for the MD students. So it's not like some talk that you hear in a conference, more like a class for basics, basic stuff. So we'll be looking at the serious tumors of the ovary and this is our hospital on the left side. Okay. So, and this is the WHO classification, the blue book. So if you look at the epithelial ovarian tumors, they are classified as benign, borderline and malignant and you have the various histotypes there. And the most common of them being the serious tumors. So when you look at the serious tumors of the ovary, you have the benign end of the spectrum, you have serious cystadenoma. And at the malignant end, you have the most malignant being high grade serious carcinoma and then we have the low grade serious carcinoma and something in between them is the serious borderline tumors. Now there's nothing much to say about serious cystadenomas, adenofibromas, surface papillomas, et cetera. You just see these benign epithelium, serious kind of epithelium. And if it is entirely cystic, it's a cystadenoma. If you've got a fibromatostoma, you would call it an adenofibroma and so on and so forth. But let's spend some time on serious borderline tumors. So by definitions, SBT as in now called are non-invasive low grade proliferative serious neoplasms. They're tumors that display greater epithelial proliferation and cytological atypia than benign serious tumors, but less than low grade serious carcinoma. This is the definition in the blue book. So if we look at some of the gross pictures of images of the serious tumors, they're usually any size, but generally larger than five centimeters, about a third of them are bilateral. Most of them are predominantly cystic. So you could generally there are multiple cysts there. The outer surface may be smooth or papillary. And if you look at the inner surface, it started with these papillary excrescences, which can be just pinhead to several centimeters in size. So here is one tumor that has a very significant surface component or an exophytic component. And these kinds of tumors are associated with implants and we'll be talking about implants a little later. So these tumors have implants in about 50 to 70% of the cases as compared to somewhere around 15 to 20% in tumors that are completely inter-cystic. So here's another case, just to show you a bilateral tumor. This was on the right side and this is on the left side, which again had an extensive surface component. And this of course is the omentectomy that's been done. So this is SBT to show you the epithelial proliferation. So in contrast to the serous cyst adenomas, it's a very simple kind of epithelium there. Here you have these complex branching papillae, which display hierarchy. Hierarchy from large to progressively smaller papillae terminating in detached tufts of cells, as you can see that. So here is again, just to show you the same hierarchical arrangement, which is very important in serous borderline tumors. So these are the different types of serous epithelium. You can have them tall columnar with the ciliated epithelium there, or you can have this kind of a hobnailing and more secretory snouts can be there. Both of them are types of serous epithelium. Just to show you another image to show you significant epithelial stratification that occurs or pseudostratification that is seen in these tumors. The cellular atopia can be mild to moderate. So you have this, sometimes these kinds of cells which are showing slightly enlarged hyperchromatic nuclei, small nucleoli can also be seen. Now, what is important is that there should be no stromal invasion. So how does the pathologist evaluate stromal invasion? They look at the epithelial stromal interface to look for evidence of invasion. Now, something like this is not really invasion. These are dips of this epithelium into the underlying stroma. Now, this is in comparison, a low-grade serous carcinoma, which is showing us invasion on the right side. And I'll be showing you more images of that. So these, when you have invasion, you have an altered stroma. You also have this retraction artifact around these nests of the tumor cells, which go budding off into the stroma. So again, these are some images which are not invasion. And of course, I've shown, and some mere presence of soma matis classifications is not invasion. But what is invasion is something like this, which is seen in a low-grade serous carcinoma. Then we have another variant called the micropapillary variant, which has these elongated micropapillae without the stromal cores. They're quite long, slender papillae, five times longer than wide. And one needs to have the micropapillary architecture in more than 10% of the tumor area to label it as the SBT micropapillary variant. Now, in contrast to the usual ones, these papillae have a non-hierarchical. In other words, they don't go from large to progressively smaller. They're kind of more or less of the same size, and they can have moderate degree of nuclear atopia. So again, look at these long, slender papillae without the stromal cores. And this is the word they are even referred to as having a medusa head appearance, this is the Greek, in Greek mythology, you have this lady who has all these kinds of things. So this kind of resembles a medusa head and is called medusa head appearance. So this, again, another image reiterating the same findings. Sometimes you can have fusion of papillae, which give a slit-like glandular spaces or a crib reform pattern. And you can also see somatosomoma bodies can also be seen focally. Now, this variant is a more aggressive tumor in stark contrast to the usual kind of SBT, and it is the type which produces invasive implants more often. So that was in some of the studies, but some other studies disagreed with that, and they contended that the overall survival rates are not very significantly different from other in SBT, provided, of course, there are no, it depends on what kind of implants they actually throw in. So if there are invasive implants, which is more common with SBT micropapillary, you would then label that as a low-grade serous carcinoma. So what is important is that thorough sampling is very important in this variant to make sure that we don't have a invasive carcinoma there. Another thing is about serous borderline tumors are SBTs with microinvasion. Now, in contrast to micropapillary, which has more aggressive tumors, et cetera, the microinvasion is not that bad. So this is the kind of picture you have in microinvasion. You have clusters of cells within the stroma, and these cells themselves have abundant eosinophilic cytoplasm, and they can have this retraction artifact. They're believed to be terminally differentiated or senescent cells. Another of one of our cases, which had microinvasion, which is, again, not as sinister as micropapillary, the outcome is similar to those without microinvasion. Occasionally, you can have SBT with lymph nodal involvement. Again, it doesn't really impact the outcome of survival. Now, when you do IHC, immunohistochemistry, on serous borderline tumors, they're positive for WT1, which is a marker of serous differentiation. The P53 is of the wild type. When we say wild type, it's a normal, non-mutated P53. So a few nuclei would be brown. The rest are all blue there. And ER can show positive in a good proportion of nuclei and PR, so would PR be there. So let's move on to what are implants. So previously, implants were divided as non-invasive or invasive implants. However, people realized that what they were referred to as invasive implants behaved very similarly to low-grade serous carcinoma. And so now, what we used to call as invasive implants, we now simply call them as low-grade serous carcinoma. When we use the term implant, it's by default, it refers to a non-invasive implant. So invasive implant is low-grade serous carcinoma. Simply, if you use implant, it always by default means non-invasive, okay? So then this is, for example, a typical implant, which is seen in the omentum. This is a non-invasive implant. It simply resembles the serous borderline tumor, but in a much, you know, in a miniature form. And in about 13% of the cases, such implants may be seen. They can be epithelial. This is an epithelial implant, and this is at higher magnification to show you an epithelial implant. And on the other hand, you can also have something called desmoplastic implants, wherein there's a lot of this kind of surrounding stroma shows this kind of pattern. But on the other hand, here is an implant, for example, but it's this very haphazard arrangement, and you can see it's very irregular groups. This stroma is also altered, it's different looking. Now, this is an example of an invasive implant. So if you have an invasive implant, you would label this as a low-grade serous carcinoma. And so this was a case where in the ovary, it was a serous borderline tumor, but the implant is now what we called it earlier as an invasive implant. We would be simply calling it as low-grade serous carcinoma. And quite often you do peritoneal washings as part of the surgical procedure, and we look at these in the lab, and this is just an example of the peritoneal washings. We see a lot of these clusters of cells, and these will be reported as positive for neoplasm. So this was a tumor, you know, which showed these exophytic component, the peritoneal washings, showed these clusters of the neoplastic cells. So we report it as positive for neoplasm. We don't call it positive for malignancy. Now, peritoneal implants, again, as surgeons, you must extensively sample the cul-de-sac, the pelvic peritoneum, the peritoneal surfaces, and also the omentum, and also the pathologist should liberally sample the submitted specimen to look for these implants. Now, going back to low-grade serous carcinoma. Now, low-grade serous carcinomas can show some areas which resemble serous borderline tumors, but of course, what distinguishes them, we've already said, is the stromal invasion. So here on the right side, lower aspect, you are seeing definite stromal invasion. Now, as far as frozen sections for borderline tumors, serous borderline tumors, well, the pathologist can sometimes say it's benign, or sometimes you would get a report as definitely borderline. However, there are no invasions in the section study. You must realize that there are limitations. We can only study maybe three to four sections in the limited time. So very often, about a third of them can get upgraded to an invasive tumor on further sampling. So with that limitation in mind, you should send a sample for frozen section, keeping in mind the limitations of frozen section in this setting. Now, I'll skip this slide in the interest of time. And then, of course, the overall survival of borderline tumors are obviously much better than their invasive counterparts. Then we move on to low-grade and high-grade serous carcinomas, moving on to serous carcinomas. Now, here is a typical gross of a low-grade serous carcinoma, which is more solid in appearance. You have this appearance here, non-hierarchical papillae, which can be fused there. There can be areas with glandular differentiation, but remember that the nuclei are all low-grade. So when we call it low-grade, the nuclei are low-grade. You can find papillae, you can find somomatous calcification, and, of course, you also find stromal invasion, which I have already described to you. So this is omental metastasis in a case of low-grade, and some of these tumors can show extensive somomatous calcification as well. So if you look at the IHC markers, WT1 would be strongly positive. It's a marker of serous differentiation. And P53, you see, will be kind of heterogeneous intensity and variable numbers. Generally, anywhere between 5 to 15 to 20% of nuclei would be positive, and this is called the, we call this as the wild-type immunoreactivity. So a low-grade serous carcinoma generally has some areas which resemble a serous borderline tumor. Sometimes you can get some areas of infarction-type necrosis, and this is, again, just to reiterate the findings that we see as pathologists in a case of a low-grade serous carcinoma. Now, again, peritoneal washings can be positive, and this was one such case wherein the peritoneal washings were positive and confirmed on histopathology. So we move on to high-grade serous carcinoma, which is a very common tumor all over the world. And, of course, when you see all these plots by the WHO wherein they refer to as ovarian cancer, remember the bulk of it is actually high-grade serous carcinoma. It's, of course, a lethal malignancy, and, of course, in India, it's really the third most common. I don't know what is the incidence in Uganda. You can tell me about it later. And the mortality is extremely high. So look at this. This is an image of the gross picture of a high-grade serous carcinoma, and the fallopian tube ephimbria has completely gone into the tumor. You know, it's incorporated within the tumor. So you always look outside to look carefully for any capsular breach, and generally, this is a solid cystic tumor with numerous papillary excesses. There are areas of hemorrhage and necrosis, and the cut surface, very dirty-looking tumor there. So this is very important, is the specimen integrity for the pathologist to comment upon. So, for example, here is a salpingofrectomy specimen. We received this as a frozen section, and the capsule is pretty much intact, and the fallopian tube, you can see, is stretched over the ovarian mass. Now, here, I've just put two gross pictures. So this, on the left side, upper aspect, is a true rupture of the capsule, okay? So this will upstage the tumor. So the tumor has literally come out of the capsule, but here, this is actually not on the right lower image. It's a sharp, clean edge. This is an intraoperative. Accidentally, the surgeon's given a nick, I suppose, and this is, you should be clear that what is an intraoperative rupture, a clean cut like this versus a true capsular involvement. So these are the various patterns. You have papillary pattern, glandular pattern, papillary, glandular, labyrinthine, crib reform arrangement, and it has got high-grade features. Micropapillary areas can be seen, solid areas, some appear spindly like this. The nuclear grade is always high. So that is what actually defines a high-grade serous carcinoma and distinguishes it from a low-grade carcinoma beside other things. So you see plenty of mitosis. You see these dark ones are apoptotic nuclei. You also see this mitosis, as you can see here, very coarse chromatin, very pleomorphic nuclei can be seen. And where you see papillary arrangement, they are non-hierarchical papillae. You can see areas of tumor necrosis. There is threefold anisonucleosis, numerous mitosis, apoptosis, et cetera are seen, which is a feature of high-grade serous carcinoma. And what defines, again, this tumor is the P53, which is seen diffuse strong positivity in nearly more than 80% of the nuclei. And intensity, the staining intensity is quite homogeneous. So this is very characteristic of the high-grade serous carcinoma. And we'll talk a little bit also about its pathogenesis. I hope I have time here. Otherwise, I can even stop here and take a break. Is it okay to continue? Yeah, go ahead, Dr. Radhika. Okay, so this was the old theories, you know, that the serous carcinoma arises from the variant surface epithelium and all these junctional epithelia, et cetera, et cetera. And the various hypothesis, incessant ovulation, hormonal stimulation, inflammation, gonadotrophin stimulation, all these were, you know, hypothesis put about nearly, maybe even when we were residents, this is what was taught to us. But over time, nothing was shown, demonstrated. There were no dysplastic changes, no P53 or expression in the ovarian surface epithelium. And then, of course, people started realizing that women with BRCA mutations have a high risk of developing serous carcinomas. And in these women, they are subjected to risk reduction, prophylactic salpingofrectomies. So at the beginning of the turn of this century, when they looked at such tumors, they found occult carcinomas involving the fallopian tubes in good proportion of these BRCA1,2 women who carry these mutations. And that gave rise to the hypothesis that the tubal fimbria is the site of origin of at least a proportion of ovarian serous carcinomas. And this is the very important paper by Christopher Crumb in Boston and this group there, that the tubal fimbria is the preferred site of carcinoma in women with the familial ovarian cancer syndrome. And then they went on to describe this protocol called CFIM, which is sectioning and extensively examining the fimbrial end of the fallopian tube. And of course, in their study, they went on to show that all the tumors arose in the tubal fimbria. And this is the protocol that we follow regularly in the histopathology lab. When you send the tumors, that the fimbrial end should be transected there. And then we have multiple longitudinal sections and the rest of the tube is subjected to transfer sections and so are the ovaries and they're completely examined. And then they went on to describe the precursor lesions of high-grade serous carcinomas, that is serous tubal intraepithelial carcinoma. And they stained the sections with P53 and also a proliferative marker called Ki67. And so they went on to... So this is, for example, these are the precursor lesions. So number one is a P53 signature. This is all in the fimbrial. The site is the fimbrial end of the fallopian tube. That's where everything is happening. So you have the P53 continuous, P53 positive nuclei there, but the MIB1 index or the proliferative index is low. So they called this lesions P53 signatures. And then if you had P53, the mutant type, and you had a high MIB1 index, they call these lesions tubal intraepithelial carcinomas. Some cases, the P53 can be completely absent and we'll see why it is. Because certain mutations will lead to zero expression of P53, but the MIB1 index is high. So this is also a kind of tubal intraepithelial carcinoma. And these were described beautifully in their papers. So this is an example of stick lesion. So you have markedly atypical tubal epithelium, high NC ratio, loss of polarity, variable stratification. And of course we identify them by the P53 and Ki67. So just to show you the CFM protocol that we employ in the lab. So this is the normal fibrillary epithelium, pallipine tubal and various, I've just shown you some stick lesions there in some of our cases. So the P53 is of the mutant type, the Ki67 or the MIB1 index is more than 10%. Here is one case on the top and here is another case of stick lesions. Now, another precursor to stick is the secretory cell outgrowths or scouts, which identified by BCL2 positive. So this is again, one people believe that initially you have secretory cell outgrowths. And then of course you have the P53 signatures and then you have the stick and an intermediate lesion is called the, these are called TILs, so the tubal intraepithelial lesion in transition. Then you have the stick, which is a true precursor of the high grade serous carcinoma. And this is again a very famous paper by Shee and Pullman published in 2016, telling you that all these, the so-called high grade serous ovarian carcinomas actually arising in the femoral end and these go cells go and drop onto the ovarian surface and actually cause the ovarian tumor, okay? So this has got implications for reporting of histopathology. Now, if you look at the ICCR or the CAP recommendations assignment of, you have to assign the site of origin of the tubal ovarian and peritoneal carcinomas and this is the algorithm we follow. So if you have, so predominantly I would say that most, you would call it as fallopian tubal origin if there is a stick lesion or an invasive carcinoma or you have a dominant tubal mass or a tubovarian mass, you would put it into the primary, the fallopian tube origin here, okay? But if you had an ovarian mass, but there was no stick in and both the tubes have been completely evaluated, you have a dominant ovarian mass, then only it would be considered as primary ovarian in origin. And if again, the ovaries were, and the tubes are completely evaluated, there is no stick or invasive carcinoma in any other place except in the omental mass, then only these tumors would be classified as primary peritoneal in origin. So if you use this classification, nearly 60 to 70% of the high-grade serous carcinomas would be shown to be of fallopian tubal origin, ovarian origin in about 20 to 30%, and primary peritoneal would anywhere vary between 10 to 20% of the cases. I can even stop here. It is little bit more only about p53. So this was the landmark publication again, which said that TP53 mutations are very important in high-grade serous carcinomas. So that is kind of, it is present in more than 90% of the tumors. And that is why I showed you some images of p53. So this is the normal, which is the wild type I refer to. In the abnormal patterns, you have the overexpression pattern, which I shown you, and sometimes you have a complete absence, okay, which is also abnormal, which is also referred to as the null type pattern. And very rarely in one to 2%, you have a cytoplasmic staining. And these three patterns correlate to the p53 mutations present in this tumor. And again, this is a very nice paper by Martin Pobel, which correlated the mutations with the IHC patterns. Next comes the role of neoadjuvant therapy. And I don't know, but at least a proportion of these cases, anywhere between 1 4th or approximately 20 to 30% of the cases, it would be difficult to perform upfront surgery and the candidates for neoadjuvant therapy, neo-NACT, which is not inferior. There are many non-inferiority trials. So this is what is done, three cycles followed by interval debulking surgery. And so how would you diagnose? So whenever you administer NACT, it's very important that a co-needle biopsy is advocated from the dominant mass lesion. Sometimes in our setup, we also do a cell block, which is obtained by a fine needle aspiration. Of course, besides that, you would be working up the cases or using the CA-125 and also in aging studies. So just to illustrate to you, a 29 year old lady, core biopsy was taken. We also had a cell block there. So it was classically a high grade serous carcinoma there, which was PAX8 positive. Now PAX8 tells you it's of malaria origin. This is the WT1, which tells you it's serous histology. And here the P53 was complete absence, a null pattern or complete absence type. Of course, because it was null pattern, we went on to do P16, which is strongly and diffusely positive. So in this setting, also we use P16. Another case where we have a lot of ascitic fluid, which is positive for malignant cells, high CA-125. So here we went and did what is known as a cell block, because this, she was a candidate for neuroadjuvant chemotherapy, came with massive ascites. So on the cell block, this is the cell block. We go and run, sorry, run these markers. PAX8, nicely positive. WT1 is also positive in the P53. Shows a mutant pattern. So you could go and attempt a nomental true cut biopsy or biopsy from a dominant mass if it is present. But sometimes if it is not possible, you could, the patient can be started on neuroadjuvant therapy if you have done this workup on the fluid. And we just have this publication in this. So whenever a neuroadjuvant chemotherapy is given, the patient would undergo interval debulking surgery. So this is the omentectomy specimen, very important. We have to take four to six sections at least as per the recommendations. So this is in the same lady. So this is the tumor in the ovary, high-grade C-fibrosis carcinoma. So then we did the CFIM. So there's a tumor in the femoral end of the fallopian tube. So obviously it is arising from the fallopian tube. And then comes the omental sections, wherein what we have to provide is the chemotherapy response score. So there is some tumor, but there are also some chemotherapy associated changes. And again, I'd refer you to this very nice paper by Baum et al., the first paper. Navina Singh is the senior author. We have also Blake Giltz. And they describe the chemotherapy response score, which is a very simple score. So CRS1, 2, and 3, if there's one, there's plenty of tumor. She's a poor responder. At the other end, three, no tumor. She's a good responder. And in between you have two, which is some tumor. So yes, tumor, no tumor, and some tumor. So why do we do that is because CRS3 identifies patients with low probability of primary platinum resistance disease, and they tend to have greater platinum-free intervals. So here in our case, it was a case of CRS2. So just for a recap, that is CRS2. Here is CRS3, with all these tumor, the regressive changes due to the chemotherapy, completely the tumor, the tumor is being knocked out. Whereas here, of course, in CRS1, there's plenty of tumor. So this is, again, there is a systematic review and all that. And last, the HRD-10 is a high-grade serious tumor. Just to illustrate a case, a lady with a breast carcinoma, she had a triple negative breast cancer. The CFIM-RRSO showed tumor. It had a stick lesion there. And then, of course, she was shown to have a BRCA1 mutation. Here's another case who had a high-grade serious tumor in the fimbria of the fallopy tube, and also in the ovary. Also, she had a BRCA1 mutation. So in these women with BRCA1 or 2 mutations, some patterns have been described, ovarian tumors, which is a solid pattern. You have something called an endometrioid, pseudo-endometrioid pattern, or a transitional pattern, the set patterns. Overall, just to give you a summary, about 15% of the patients with high-grade serious carcinomas can have germline mutations. Additionally, another 10% or so would have somatic mutations in BRCA1 or 2. Some others can have BRCA1 methylation and genomic aberrations in the homologous recombination genes can also be seen. And why is it important? Because they respond to PARK inhibitors, and these are beneficial as maintenance therapy to improve the progression-free survival in high-grade serious tumors. So this is the last thing. So whatever we talked, the low-grade serious tumors belong to the type 1 tumors, whereas the high-grade belong to the type 2, and these are the genetic and the molecular alterations. You have all these, which I spoke to. So I come to my last slide. Sorry if I exceeded time. So ovarian carcinoma arises from the fallopian tubal fimbria in a good number of cases. So the pathologists evaluate the tubes by the C-FIM protocol, and we have to mention the probable site of origin in our report. We do the p53-IHC, which is a surrogate marker for the TP53 mutations. And of course, wherever you have to do, when NACD is given, we have to comment on the chemotherapy response score on the sections of momentum. And the pre-NACD diagnosis is obtained by a core biopsy, and the IHC panel is PaxA, WT1, p53, and p16 in the null type and, of course, is a big role. Nowadays, it's very routinely done for homologous HRD, the repair deficiency genes, particularly BRCA1, 2, and a few more genes which are done in these patients. Thank you very much. It's over to you.

serious tumors

borderline tumors

low-grade proliferative tumors

histological characteristics

stromal invasion

immunohistochemistry

molecular markers