The International System for Reporting Serous Fluid Cytopathology

October 18, 2021

Information

October 14, 2021

Yale Pathology Grand Rounds

Ashish Chandra, MD, DNB FRCPath DirRCPath (Cytol)

ID7048

To CiteDCA Citation Guide

00:09I think you should go ahead baby.
00:12Yeah, thank you. So thank you
00:14everybody and it's my great pleasure
00:17to introduce Dr Ashish can a gender
00:21I hope it's right pronunciation.
00:25Ajendra got a medical degree from
00:29University of Delhi in 1989 and got
00:33a FRCP diploma in Psychology in 1960
00:37and diploma in histopathology in 2000.
00:41He is a very active leader nationally
00:45and internationally in the field,
00:48both psychopathology and
00:51Europe urological pathology.
00:54He published 100 publication.
00:57I hope I'm right.
01:00182 publication and thank you
01:02and he is the deputy editor
01:05for very procedures anthology,
01:08journal Psychopathologie, he's.
01:10Executive Member of British
01:14Association of Psychopathology,
01:16and more importantly,
01:18he is the vice President of International
01:22Academy of Psychopathologie and
01:24its chairperson elect for British
01:28Association for Urological Pathology.
01:30He has participated in so many
01:34terminology inside pathology,
01:37including professor system for
01:39thyroid Paris system for urine.
01:42Menards system plan and and
01:46International Classification of zeros.
01:49I don't know what is next,
01:50but anyway, let's wait.
01:52So we are very fortunate to have
01:55a she's here to talk about the
01:58International classification
01:59of serious set of pathology.
02:01Thank you.
02:06Thank you so much Doctor Wang for
02:09that very kind introduction and
02:11thank you Doctor Prasad for inviting me
02:14to contribute to today's grand round.
02:16It is my great pleasure and privilege
02:18to be speaking to an audience at the
02:22prestigious Yale University and I would
02:24have loved to have been there in person.
02:27But of course you know times don't
02:29allow that. So as it happens,
02:31I'm attending a an executive board meeting of
02:34the British Association of Psychopathology.
02:36Today, not in London,
02:37but in Nottingham and so I'm
02:39sitting here from my hotel room,
02:42which is why it might.
02:43I might appear to be sitting
02:45in a dark room somewhere.
02:47But we've just finished a board
02:50meeting and I'm here at your
02:53disposal to introduce you to the.
02:55International system for reporting
02:58serious fluid psychopathology.
03:00So this was announced in active
03:03cytological in June 2019 and I'm very
03:06pleased to say that the book is now
03:10available both as an electronic book as
03:13well as in paperback through Springer.
03:17Who are the publishers?
03:19And if you do decide to buy the book
03:21please do buy it from Springer and not
03:24other websites which are more expensive.
03:26It is my duty to first acknowledge
03:30my Co editors, Dr.
03:32Barbara Crowther's,
03:33doctor Daniel Curtis and abroad
03:35Dr Fernando Schmidt who were the
03:39leading lights in bringing this this
03:42project together which is jointly
03:45sponsored by the American Society of
03:47Cyto Pathology and the International
03:50Academy of Psychology and I'm very,
03:52very much indebted to all the chapter
03:55authors who have contributed.
03:57To this book,
03:59during a particularly difficult time
04:01over the pandemic, and we were very,
04:05very fortunate to see it come to
04:08fruition and publication at the
04:10end of last chair.
04:12So what was the need for this project?
04:15You know, we when we thought about,
04:17you know,
04:18do we really need a terminology
04:20system for serious fluid cytology?
04:23We had to have a discussion I had
04:25to put forward a proposal to say,
04:27you know?
04:27What would be the point of doing
04:29this and what motivated me was
04:31the need for some answers to very
04:34practical clinical questions.
04:36The parish system had set a really
04:38good precedent to evaluation of
04:41adequacy criterion, fluid samples,
04:43urine in the case of the parish system
04:46and had linked it to volume and celularity,
04:49and to my mind there would was a link
04:52to fluid samples and adequacy taking
04:55into account both volume the cell content.
04:58And this in turn I thought would help
05:00us define what is a true negative
05:02sample for a particular patient.
05:04That is to say,
05:05if the cytology sample from
05:06a pleural fluid is negative,
05:09then it does in fact mean that
05:12the patient is free of metastatic
05:15disease to the pleural cavity.
05:17There was also the issue of the use
05:20of the existing terminology systems,
05:23which weren't internationally accepted,
05:25so everyone was doing their own thing.
05:29In particular,
05:30the tippy and suspicious categories
05:31showed a great degree of overlap
05:34in published literature,
05:35and I thought that the time had
05:37come to try
05:38and define a tipiya and suspicious.
05:41As you know, individual categories and define
05:44some criteria for putting cases into these.
05:47Categories I also thought that visiting
05:50revisiting the value of cytology in Miso,
05:53thi Lio Ma was very timely.
05:56Now, given that the diagnosis of mesothelioma
05:59rests on ancillary work up and fish,
06:03and although the gold standard
06:06still remains a biopsy,
06:08I do not contest that.
06:09But it is possible to reach a
06:12conclusive diagnosis of mesothelioma
06:13based on a psychology sample.
06:16And then there was this, really.
06:17Tricky question about peritoneal washings
06:20and how to report the presence of
06:23epithelial cells in these specimens.
06:25So there were a good number of reasons
06:28in the proposal and I was very,
06:29very pleased that both the American
06:32Society of Psychopathology and
06:34the International Academy thought
06:36this was a project worth doing.
06:38And So what does the system look like?
06:40Happily,
06:41it is a very familiar looking terminology
06:45system where you have the nondiagnostic.
06:47Category or and where you have the
06:51negative for malignancy category
06:53followed by atypia suspicious.
06:55Just like you have in Paris,
06:57Bethesda Thyroid and Milan terminologies.
07:00With the only difference being that
07:03the malignant category in fluid
07:05cytology is split into primary,
07:07which of course includes MISO.
07:09Thi Lio,
07:10Ma mainly and also secondary which
07:12includes metastatic cost numbers
07:14but also secondary involvement by
07:16hematopoietic neoplasms such as leukemia.
07:18And then foamers and hence the choice
07:21of secondary rather than meta static.
07:25So what are the factors involved in
07:28adequacy in serious fluid cytology samples?
07:30As I said, there's of course sample volume,
07:32but then there's also sell
07:35content and cellular preservation.
07:36So is there a recommended volume
07:39for serous fluid samples?
07:41Was the question that we wanted to answer,
07:43and for this there was already existing
07:46evidence that came from Doctor Ruper
07:49at all from Johns Hopkins who had
07:51demonstrated through a very large
07:53volume study of big sample size.
07:56That 75 male was probably an optimal
08:00volume for psychological assessment
08:02and exclusion or confirmation of
08:04milling malignancy between 50 and 75
08:07was probably an acceptible volume
08:10to request the clinicians to send
08:13for psychological evaluation in
08:15a couple of years time.
08:16They also published data to
08:18show that for pericardial fluid,
08:2060 mil was an acceptable volume,
08:23but that is not to say that smaller
08:25volume samples should be rejected.
08:27Perhaps you know everything does have
08:29have to be booked in and accessioned in
08:32the cytology laboratory and reported upon.
08:34But if the sample volume is very small
08:37and normal agency is demonstrated,
08:39then perhaps a comment is warranted
08:41to say that you know if the clinical
08:44suspicion of malignancy is high,
08:46then perhaps a 50 to 75 mil volume
08:49of sample should be sent.
08:52Also,
08:52on that point worth mentioning that
08:55aliquoting specimens for other
08:57investigations on serious fluid samples
09:00such as microbiology and biochemistry,
09:03should all be done at the same time.
09:06So when you collect the sample from the
09:08patient on the ward or in the clinic,
09:10split it up into sample to go to
09:12psychology and biochemistry and
09:14microbiology separately and not send
09:16it all to microbiology and expect
09:18them to then split it and send it to
09:21cytology and biochemistry because.
09:22That delay of course causes a
09:25deterioration in the quality of
09:27the sample for cytology and equally
09:30for microbiology or biochemistry.
09:32Cell content.
09:33Big question was do we have to see
09:36me that email cells in serous fluids
09:38in order to call them adequate?
09:41And the short answer to that is no,
09:44you don't because it is completely
09:46acceptable to find only lymphocytes,
09:48say in a tuberculosis or chylous effusion,
09:51or neutrophils,
09:52or in an empire from an acute
09:55bacterial infection,
09:56and you may have benign effusions
09:59without major female cells.
10:00So and conversely,
10:01also you could have malignancies
10:03where there's a single cell.
10:05Population of malignant cells only,
10:07without mesothelial cells,
10:08so it's nice to see me the serial
10:10cells because it does give you the
10:13confidence that the the plural or
10:15pericardial or peritoneal cavity
10:16has been sampled,
10:18but you do not pronounce the specimen
10:20as being non diagnostic simply because
10:22you don't see me as a theory of cells.
10:25Perhaps the most important feature,
10:28very much like FNA samples or samples
10:32fluid samples from other sides you know.
10:35You could have a very cellular specimen,
10:37but it is poorly preserved and it
10:39could still be non diagnostic and
10:41this could be because there's a
10:43loss of quality
10:44due to degenerative changes because
10:45of delays in reaching the laboratory.
10:48There could be bacterial overgrowth and of
10:51course technical artifacts and contaminants.
10:54So I'm going to walk you through the
10:57terminology system using six cases,
10:59one for each of the diagnostic categories,
11:01and then at the end.
11:02I'd be very pleased to take any questions
11:05during the time that we have a discussion,
11:07so let's start with the first case of 54
11:10year old man with a left sided pleural
11:12effusion is a smoker and suffers from
11:14cough and chest pain for one week.
11:17I will take a moment here to talk
11:19about the importance of macroscopic
11:21findings in serious effusion samples.
11:24Because this is frequently overlooked,
11:26as soon as we get the request form and
11:28the slides we read the clinical data
11:30and we start to look at the slide,
11:33perhaps without even turning the form
11:35over or scrolling down the screen to
11:37see what was the macroscopic appearance
11:39of this fluid or cytotechnology
11:41colleagues work very hard in the
11:43laboratory to record the volume and the
11:46physical appearances of old samples,
11:48in particular fluid samples,
11:50and their descriptions are important
11:52and clinically.
11:54Meaningful so you could have,
11:55you know a stroke alert fluid,
11:58which is probably just a a transit date.
12:00Or you could have apparent diffusion,
12:03which is almost certainly an exit date.
12:06You could have a heavily bloodstained fluid
12:09you could have Milky or chylous fluid,
12:12and all of these words have meanings
12:14and so it is important to look at the
12:18macroscopic appearance of the sample and
12:21also in the light of what I've just said.
12:24About the volume of sample to see
12:26if a sufficient sample was sent,
12:28because based on a small volume sample you
12:31may not get the full representative picture.
12:34The second point I want to mention
12:36on this slide again is the the fact
12:39that you should ideally examine
12:41a combination of a panda.
12:42Games are for serious fluid cytology samples,
12:45pretty much the same as you probably already
12:48do for FNA samples from various sites.
12:52So it doesn't matter.
12:53What the PAP stain is,
12:55whether it's on a direct spread or it's
12:57on a cytospin or it's a liquid based
13:01preparation such as either thin prep
13:03or show pad up app is a PAP and in
13:06the same way your romanowsky based dye
13:08orgainzer stain could either be a diff,
13:10quik or hemo color or main may Grunwald
13:13games are preparation so as long
13:15as you are using a combination of a
13:19romanowsky die and a PAP you should get
13:21the best information on that particular.
13:24Sample having said all of that,
13:26in this particular case, of course,
13:28you probably don't even need to put
13:29this slide under the microscope,
13:30because you can simply look at it,
13:32glance at it,
13:33hold it up to the light,
13:34and say there's not much there.
13:35It looks like there's probably just
13:37some lies.
13:37Red blood cells at the periphery
13:39of this thin prep,
13:41and there are no major fetal cells
13:43or macrophages or any other kind
13:46of cells to give you any confidence
13:48that this is a representative sample.
13:51It's probably just a traumatic aspirate.
13:54And therefore nondiagnostic,
13:55even on the games are,
13:57you will probably just see a red
14:00and white cells. Again.
14:01A point to mention at this step is
14:04that when you see the neutrophils and
14:07lymphocytes which are probably all
14:09just part of the peripheral blood.
14:11Don't call them inflammatory
14:13cells because that to a clinician
14:15breeds like oh so there is an
14:18inflammatory pathology in this sample.
14:19These are simply white blood
14:21cells from the peripheral blood.
14:22They're not indicative or a
14:24pathology in the pleura,
14:25so you know simply calling it blood
14:28and non diagnostic is adequate.
14:30Rather than listing all the white blood
14:32cells that you might be seeing on the sample.
14:35So of course the terminology systems
14:38are all about standardizing,
14:40uh, you know, reports,
14:42and so the structure of a report,
14:45whether it's Paris but Esther or Milan,
14:47follows a certain protocol,
14:49and so the sample report here
14:52should include an adequacy comment,
14:55a diagnostic category,
14:57and a clinical comment where appropriate.
15:00So in a case like the one I've
15:02just shown you,
15:03a sample report might read as follows
15:06evaluation limited by heavy blood staining,
15:08likely non representative sample
15:10and it is then assigned to the non
15:13diagnostic category in the international
15:15system and as a clinical comment you
15:18would be advising for repeat sample
15:20and stating in your report until your
15:23clinicians begin to get used to the
15:25idea that they really need to try
15:27and send 50 to 75 mil volume sample.
15:30And not just two or five mil of sample
15:33'cause they may not get their answer.
15:36So that was nondiagnostic
15:38moving on to case number two,
15:40and here's a clinical history of a 64 year
15:43old man with liver cirrhosis and ascites.
15:46We've got 60 mil or straw colored
15:48fluid and two sided spins have
15:50been prepared a PAP and a games.
15:53A combination as I said is ideal and here
15:56on this games of preparation you can see
15:59some beautiful basophilic mesothelial cells.
16:02You will appreciate their peripheral,
16:06Lacy borders.
16:07You could appreciate.
16:09Perhaps there are the gaps or windows
16:12between the mesothelial cells,
16:14the music penal cells show,
16:16or two tone staining
16:18pattern of the cytoplasm,
16:20their nuclei,
16:20or very much of the same size and
16:23shape without much pleomorphism,
16:26and they are infiltrated by these
16:29neutrophils and lymphocytes.
16:30So there is this interaction between the
16:33inflammatory cells and mesothelial cells.
16:36You can appreciate the same features.
16:37On the papanikolau cytospin,
16:40where again you are able to pay more
16:44attention to the nuclear detail,
16:47which is the strength of the PAP
16:48stain and you will see that the
16:51nuclei have very smooth margins.
16:52The nuclear membrane is very regular,
16:55the chromatin is finally dispersed
16:57with the presence of small multiple
16:59nuclei rather than a single
17:01large prominent nucleolus.
17:03And again, these groups are
17:06infiltrated by inflammatory cells.
17:08So no obvious signs of malignancy.
17:13The sample is certainly
17:14adequate for evaluation,
17:16and you saw some neutrophils,
17:18mesothelial cells, and lymphocytes,
17:20and so this will go into the
17:23negative for malignancy category.
17:25And given that there was a history of
17:27cirrhosis and ascites in this patient,
17:29you could put in a comment about the high
17:31proportion of neutrophils being present,
17:33which may represent spontaneous bacterial
17:36peritonitis and therefore correlation.
17:38With clinical and microbiological
17:40findings would be advised.
17:44So the negative for malignancy
17:47category you would expect to
17:49see normal or the expected cell
17:51populations in variable numbers,
17:53and these could be lymphocytes.
17:56Macrophages means a female cells,
17:58neutrophils and eosinophils.
18:01Doctor Evil Chick,
18:02who is one of the lead
18:03authors of the Paris system,
18:04was also the lead author for the
18:08negative for Malignancy Chapter
18:10and she created this awesome
18:14algorithm for effusions and once you
18:17separated out the inadequate ones,
18:20the remainder that are adequate
18:22could be just broadly divided into
18:25two main categories of those having
18:28the expected cellular findings.
18:30Uh, and so here you would just
18:33have variable numbers of the,
18:35you know,
18:36lymphocytes or mesothelial cells etc.
18:39And on the other hand you could
18:41have some unexpected cellular
18:42and non cellular findings if
18:45you have malignant cells.
18:47Obviously you've got a diagnosis and
18:48then you've got to do your ancillary
18:51work up to confirm the diagnosis.
18:53But you could also have some noncellular
18:55findings which do indicate a careful
18:58search in the background formula.
19:00And see because some of these
19:02non cellular findings may be
19:04associated with malignancy,
19:05but if you don't see malignancy
19:07you don't have to call the
19:09sample atypical or suspicious.
19:11You should still sign it out as negative.
19:13Having done a careful search to exclude
19:17malignancy and As for the reactive effusions,
19:21you could have different patterns
19:23based on the relative preponderance
19:25of a particular cell type.
19:27So whether it's eosinophilic
19:29or lymph ascitic.
19:30You would need to state you know
19:32what the possible causes of this
19:35cinephilic preponderance might be,
19:36whether there's been a recent
19:39pleural fluid aspiration,
19:40or whether there is an allergic
19:43condition in the patient.
19:44And likewise as I said earlier,
19:47for lymphocytic and neutrophilic effusions.
19:51So that's a negative for malignancy category,
19:55moving onto a third case.
19:56And here's the history of a 46
19:58year old female with a history
20:00of breast carcinoma six years
20:02ago and now presents with cough
20:04and a small pleural effusion.
20:05We've received 20 Miller stroke,
20:07bullet fluid and sitis pins have
20:11been prepared and on the side
20:14of spins at high magnification.
20:16This is times 20.
20:18You have a very cellular sample
20:20in the background you can see.
20:22Blood and you can see quite
20:23a few years cinefile,
20:24so it's possible that this is
20:27a repeat aspirate.
20:29In the center fielder,
20:31simply a reaction to the introduction
20:33of small amounts of air during
20:35the previous procedure and which
20:37irritates the pleura and insights
20:39in your cinephilic reaction.
20:41But what you also see are of course
20:43these means arterial cells with
20:45the gaps or windows between them,
20:47some of them showing by nucleation.
20:49Overall looking very,
20:50very bland indeed and then also some
20:53other cells which by their association
20:56with the same group of material
20:59cells are probably just degenerate.
21:01But they all showing micro valuation
21:03of the cytoplasm and and so you know
21:06there's some doubt in your mind given
21:08the history of breast carcinoma,
21:10should I really worry
21:11about these or can I write
21:13these off as degenerative
21:14changes in medial cells?
21:16And then you look at your thin prep PAP?
21:18And again you see this population
21:20of likely means arterial cells,
21:23but scattered within.
21:24These are also some cells which
21:26draw your attention because they
21:29have slightly prominent nucleoli.
21:31Although the nuclear chromatin overall
21:33is not cause and so you're not strongly
21:36suspicious that these are malignant,
21:38you believe that these amazing serial cells,
21:40but there is a clinical history
21:43that is making you pause and wonder
21:46whether you need to investigate the
21:49sample further through ancillary
21:51tests to exclude the possibility
21:53of small volume metastases from the
21:57known previous breast carcinoma,
21:59and so that is the sort of clinical.
22:01Scenario or setting for the use of
22:04the atypical category when you have
22:07occasional body preserved cells
22:08with some nuclear enlargement,
22:11subtle changes like hyperchromasia,
22:13but no obvious chromatin and
22:15nuclear membrane abnormalities.
22:18You believe that these are
22:19lightly degenerated macrophages,
22:20amazing theater cells and you're
22:23performing ancillary tests to exclude the
22:26possibility of metastatic cost Sonoma.
22:29So you do your epithelial markers
22:31and mesothelial markers.
22:33And you can then downgrade the
22:35sample to negative for malignancy.
22:37Once the epithelial markers
22:39are shown to be negative.
22:40So in this case you prepare a cell block
22:43and again all you see or miso thi lio cells,
22:45macrophages some fiber in a few
22:48lymphocytes and your epithelial
22:50markers come back negative and so
22:54the atypical category really is an
22:58uncommonly used category in effusions.
23:00Some experience title pathologists
23:02don't like to use it.
23:03At all,
23:04and in fact,
23:05one of the biggest questions for me for
23:07this particular terminology system was,
23:09could we simply just collapse the
23:11atypia and suspicious category
23:13into one and do away with it appear
23:15completely because they just didn't
23:17seem to be good diagnostic criteria
23:19in literature for a for a tipiya.
23:21However,
23:22before we embarked on the project
23:24and our literature search,
23:26we conducted a survey which was sent
23:29out by the University of Wisconsin
23:31doctor Dan Curtis's department.
23:33And we got about 600 respondents
23:35telling us that they would like us
23:38to include the tipiya category in
23:41the terminology system because they
23:42do use it and they have clinical
23:44circumstances in which they use it.
23:47And so for the time being,
23:48we decided to include it in
23:50the terminology system.
23:51But we're going to watch its progress
23:53and the performance of this category.
23:55What was becoming increasingly
23:57apparent from the survey was that
23:59in our minds we are following the
24:02two step process for the atypical.
24:04And suspicious cases where we were
24:06putting a case aside while we
24:09were doing the ancillary work up
24:11and some colleagues were actually
24:13issuing a preliminary report,
24:15which is of course optional and
24:17not mandated by the international
24:19system simply to give them the
24:23time to assess this sample.
24:25And in order to prevent, you know,
24:28clinical queries and emails,
24:30and you know where's the result to put
24:32something out there for the clinicians.
24:34To receive to say we're working on this case,
24:37there's something odd about it,
24:39and we need a little bit more time to come
24:43to a final conclusion about this case.
24:46And so the diagnostic algorithm
24:48for the atypical category really
24:51is that you you're you perform a
24:53preliminary assessment over tipiya,
24:55and then if your immuno chemistry
24:57demonstrates these atypical cells to
25:00be just macrophages or mesothelial
25:02cells you just downgrade that
25:04report to a negative for malignancy
25:06in a small number of cases.
25:07If the immuno chemistry demonstrates that
25:10the atypical cells are epithelial then you
25:13can upgrade your diagnosis too suspicious.
25:17Or malignant secondary.
25:18And then you would be left with a very
25:21small number of cases where there are
25:24insufficient representative cells or
25:26the you know chemistry is equivocal,
25:28and so you reduce the burden of the
25:31cases that you would sign out as that
25:34appear on serious fluid cytology.
25:37And so that is the kind of reasoning behind
25:40both the tibia and as I will show you,
25:44the suspicious category.
25:45In my next case,
25:47a 68 year old man with pleural
25:49fluid history of lung carcinoma,
25:5130 mil of blood tinged fluid is received.
25:54And here on the map you can appreciate
25:59that there are just two cells,
26:01but these two cells stand out
26:04in the background because they
26:06are much larger than the.
26:08Inflammatory cells,
26:09the UM, the macrophages,
26:12and the means of teal cells in the
26:14background on the games are again.
26:16You see that these nuclei, or quite large,
26:19irregular and again the cells are much,
26:21much louder than the surrounding
26:24lymphocytes and macrophages,
26:26and made me feel cells.
26:27So these three cells,
26:28or you know,
26:29on the PAP and on the games
26:31are or to an experienced I at
26:34least suspicious for malignancy.
26:36Depending on your experience.
26:38And expertise.
26:39Of course, you could say I'm
26:41pretty sure that's malignant.
26:42Uhm,
26:43you know,
26:44but I need to do my immunostains
26:46to be able to just confirm that
26:49these cells are indeed epithelial.
26:51Before I make a diagnosis of metastatic
26:54cost Sonoma in this particular patient.
26:57And so you were suspicious while
26:59you were appreciating just the uh,
27:01the cytological appearances.
27:03But you needed backup from
27:05your ancillary work up.
27:07To upgrade the diagnosis from
27:09suspicious to malignant,
27:11and so the suspicious scenarios in
27:13serous fluid cytology is where you
27:16have either small numbers of cases
27:18or groups with nuclear pleomorphism
27:20that require ancillary tests
27:22for confirmation of malignancy.
27:24Sometimes you may have cells with
27:28relatively bland appearances
27:29or mild plum Orphism.
27:31They may even be numerous,
27:33but they look very bland,
27:34or they may be simply in small.
27:37Numbers like we talked about in
27:39the case of breast or another
27:41scenario where you have music in
27:44the background but very few or
27:46no cells or very bland looking
27:48cells in ascitic fluid in say
27:50a pseudomyxoma pair tonight.
27:52But in the absence of cells you can't
27:54really make a diagnosis of malignancy,
27:56but you could certainly raise
27:58the suspicion of pseudomyxoma
28:01based simply on the museum scene,
28:04lymph ascitic effusions with
28:06the monotonous population.
28:07Again, would need a a an ancillary.
28:10Work up to confirm the diagnosis of lymphoma
28:12or exclude the diagnosis of lymphoma,
28:15and so again till you get the
28:16results of your ancillary work up.
28:18You could put that into the
28:22suspicious category provisionally.
28:23And so similar to the algorithm for
28:25atypia in the suspicious category.
28:27Again, we are basically worried
28:30about a small number of cells
28:33or preliminary assessment is.
28:36In the favor of malignancy rather
28:38than in favor of benign as
28:40opposed to the atypical category.
28:43And then once you do your immunostains
28:45you confirm malignancy and your final
28:47report would be malignant and so again
28:49you would be only left with a very
28:52small number of cases where there is
28:54insufficient material or the immuno
28:57chemistry is not supportive of the
28:59diagnosis where you would be left
29:02with a suspicious category as the
29:04final diagnosis and you could of course.
29:06Just request further sample
29:09to confirm the diagnosis.
29:11At this point I would just take a
29:13moment to talk about answer retesting
29:15of lung padmakar Sonoma in this case
29:17because in such a case you might
29:19be able to arrive at the diagnosis
29:21of metastatic lung carcinoma.
29:22A once you've done your TTF one immunostain,
29:25but you may not have sufficient
29:28material remaining for PDL 1 alpenrose,
29:30and for doing your next generation
29:33sequencing which may be needed
29:35for targeted chemotherapy.
29:36In this particular case,
29:37and so my plea to you is to restrict the.
29:41Amount of immuno chemistry.
29:43You perform in a posse,
29:46cellular samples or samples that have
29:48small numbers of malignant cells.
29:50Because you really want to try
29:52and conserve material as far as
29:55possible for molecular testing,
29:56it may still not be possible given
29:58on the small number of malignant
30:00cells in such a sample,
30:02but at least we should not exhaust all
30:05of our cells doing immuno chemistry.
30:08So just to summarize,
30:10the difference between the atypical.
30:11In suspicious categories in
30:13the international system,
30:15in the atypical category we have
30:18subtle psychological abnormalities
30:20where we think we're dealing
30:23with a benign cell type,
30:25but we can't completely or confidently
30:28exclude malignancy because there
30:31may be a clinical factor that
30:33is influencing us to exclude it.
30:35But you do expect in the vast
30:38majority of cases that the outcome
30:40would be benign and so the.
30:42Suggested risk of malignancy in this
30:44category is to the tune of 20%.
30:46This needs to be borne out by future data,
30:49but we would like to maintain a
30:51good degree of separation from the
30:53suspicious category with a sort of a 20.
30:5680 split for the suspicious category
30:58so that in in the suspicious category
31:01we really expect that the outcome will
31:05be usually be malignant because we
31:07favored an epithelial origin of the cells,
31:10but we just needed more of the same,
31:14so it's a quantitative factor
31:16in the suspicious category,
31:18whereas it could be a qualitative
31:20factor in the atypical category
31:22where the cells that you see
31:24simply do not fulfill the criteria.
31:27Or high grade malignancy and therefore
31:29you are being cautious and you know,
31:32erring on the side of caution
31:34and calling it a typical.
31:36Whereas in suspicious you're fairly
31:38confident that if you had another 10
31:40cells or if the ancillary work up proves
31:43these suspicious cells to be malignant,
31:46then you would be shown to be
31:49correct in your assessment.
31:51OK, moving on to the last two cases,
31:53then #5 is a 68 year old man with a
31:56history of exposure to asbestos and a
32:00unilateral hemorrhagic pleural effusion.
32:0280 mil of blood fluid with a clot.
32:05And again,
32:06I'm just going to take a moment
32:07to say that if there is a cloth
32:09present within the sample,
32:11the lab should really automatically
32:13process it because it's very likely
32:16that the cytospin's may not contain the
32:18material that it is trapped within the cloth.
32:21And so getting additional value
32:24from processing the cloth should
32:26almost be an automatic procedure,
32:29whereas if you there isn't a
32:31spontaneous clot and you want to
32:34perform additional ancillary work up,
32:36you could request a cell block from
32:39the sample whereby you're actually
32:41adding thrombin or other chemicals
32:43to the sample to precipitate a clot
32:46from which you can then cut sections
32:48and perform immuno chemistry.
32:51So of course you know.
32:52The history there,
32:53you know is a very directed one
32:56and it is about mesothelial cells.
32:58And here is this,
32:59you know,
33:00really happy looking miso thi deal
33:02cell that's bursting at the edges with
33:04you know it's this sort of Lacy skirt,
33:06like peripheral blips.
33:07It's got the sub membranous
33:10glycogen vacuoles.
33:10It's got the two tone staining
33:13of the cytoplasm.
33:14It's got a relatively bland looking
33:16nucleus which is showing a relatively
33:19low nucleocytoplasmic ratio.
33:21You know, there there.
33:23Chromatin and the nuclear membrane,
33:25or look relatively smooth,
33:26but by looking at it you can't
33:28always tell whether this means
33:30ethereal cell is benign or malignant,
33:32and that is the challenge of
33:35mesothelial proliferations.
33:36Of course,
33:38there are features like hypercellularity,
33:41and you know if you have presence
33:44of significant pleomorphism abnormal
33:46mitotic figures in mesothelial cells,
33:49then of course you could suspect me
33:51the thielemier straight away based on.
33:52Morphology,
33:53but usually it is quite difficult
33:56because the morphology of medial
33:58cells can be very very bland even
34:01in neoplastic proliferations,
34:03but they also tend to be relatively
34:07monomorphic from one cell to the
34:10next from 1 nucleus to the next,
34:13and from one group to the next.
34:14The groups are typically very equal sized,
34:17unlike in adenocarcinomas,
34:19and of course at high magnification
34:22they will still.
34:23Then the properties of mesothelial cells,
34:25which are the gaps or windows
34:27between the cells,
34:28the clasping feature of mesothelial cells.
34:32They may begin to show very
34:34prominent single cherry,
34:35red large nucleoli which would
34:38alert you to the possibility
34:40of mesothelioma. But you are going
34:43to need your ancillary work up
34:45to confirm the diagnosis on say,
34:48a cell block and again you can
34:50appreciate all of those features
34:51of major female cells in this.
34:53Cell block here and so this is
34:55really the the panel that will help
34:58you arrive at the conclusion about
35:00what the nature of this means.
35:02Ethereal proliferation is.
35:03Is it just reactive and therefore
35:06to be put in the negative
35:08for malignancy category and.
35:10For this, uh,
35:11this is a suggested and commonly used panel.
35:15Immuno chemistry certainly in Europe
35:17and other parts of the world.
35:19Desmin is very frequently used thinking
35:22it is quite variably used in the states,
35:25but we certainly find it very
35:27valuable because Desmond retains its
35:30cytoplasmic positivity in reactive
35:32mesothelial cells and it is lost in
35:35a high proportion of mesotheliomas
35:37epithelial membrane antigen shows a dense,
35:41very thick membranous staining
35:44in mesothelioma.
35:46Which is not seen in mesothelial
35:48reactive medial cells,
35:50and it will show a diffuse cytoplasmic
35:53staining in adenocarcinoma.
35:54So it you know this is one stain
35:56that can help you distinguish
35:57between reactive means.
35:59Arterial cells, miso, thi Lio,
36:00Mars and adenocarcinomas,
36:01but of course we are now in
36:04the day and age of BAP.
36:05One bracket associated protein one,
36:09the loss of which is associated with
36:11a very high proportion of medium.
36:13As you know 80 to 90% of me is a theomars.
36:16Will show a loss of nuclear
36:18staining with BAP one which will
36:21be retained in a reactive measure.
36:23Theal cells and also interestingly
36:26in lung adenocarcinomas.
36:27So if BAP one is included in
36:30your panel and it is positive,
36:32it's almost certainly not miso,
36:34thi Lio Ma and your panel here could
36:36then help you distinguish between an
36:39adenocarcinoma and mesothelioma and
36:41back one is quite helpful in that regard,
36:44but of course you know ancillary.
36:46Testings using fish or mtap and
36:50P16 deletions are the ones which
36:53you know will clinch the diagnosis
36:56in the equivocal cases,
36:58and so this is the panel which I
37:01would recommend and is recommended in
37:04the international system for sorting
37:06out your mesothelial proliferations.
37:09I won't read out this slide to
37:11you of ancillary tests,
37:13but just to say that a good
37:15place to start if you have.
37:17A differential diagnosis of
37:19amazing theal proliferation versus
37:21carcinoma used to good miso,
37:25thi lio and epithelial marker,
37:26and a macrophage marker user panel
37:29that works well in your laboratory.
37:31Historically,
37:31if it's worked well for you know years
37:34and years and there's no reason to
37:37think of switching to something else.
37:39But bear in mind that there are some
37:41very good adenocarcinomas that are
37:43coming up all the time and perhaps one
37:45of these could replace some of the.
37:47Older ones that you may have
37:48been using in the laboratory.
37:50I'll come to the site specific markers later,
37:52but also to alert you to the
37:54fact that there can be an overlap
37:57with certain immunostains like
37:59WT1 GATA 3 which can overlap between
38:03carcinomas and mesothelial proliferation.
38:05So you do need to be aware
38:08of published literature,
38:08and of course the importance of clinical
38:12correlation and every single case.
38:14But by and large you could
38:16perform answer retests.
38:17To resolve the dilemma between Mesothelial
38:20proliferations and metastatic carcinoma.
38:22So a sample report for a MISO thi live
38:25proliferation in the international
38:26system would read something like
38:28this satisfactory for evaluation,
38:30you would give a brief description
38:32of the cellular findings,
38:34the fact that immunostains have
38:35been requested for confirmation
38:37either on the cell block.
38:38Of course, if there is an accompanying
38:40biopsy in the same department,
38:42there probably is no need to replicate.
38:45The same immunol work up on two different.
38:48Uh, you know specimens and you could
38:51just do them on either one of those two,
38:54and then if the immunostains
38:56are confirmatory,
38:57you can have a final diagnosis
39:00of malignant primary,
39:02which is means a theory OMA.
39:03And of course always always advise
39:06clinical correlation because.
39:08Radial radiological appearance is
39:10and the biopsy confirmation of
39:13invasive mesothelioma is still
39:14the gold standard for diagnosis,
39:17but it can be achieved with cytology with
39:21a confirmatory panel of immunostains.
39:24Anything that falls short of this
39:26mark should be called either
39:28suspicious or just left at a typical.
39:30So if you've got,
39:31you know some classic morphological features,
39:33but the immunostains are not confirm
39:36atory step back and advise biopsy.
39:39Advised correlation with clinical and
39:41radiological findings discussed at the
39:44clinical meetings or multidisciplinary
39:46meetings as we call them here in the UK.
39:49And of course,
39:50if the morphology is not classic
39:53and the immunostains are not
39:55confirm atory either then you stop
39:57at a typical musical proliferation
40:00and advise further investigation.
40:02So,
40:03uhm.
40:04A recognizable abnormal cell
40:07population should be present and
40:10adequate for a robust diagnosis on
40:13which clinical management may be
40:15based in the malignant categories.
40:18The cell types should be specified
40:20either on morphology alone or
40:22supported by immuno chemistry and
40:24which would allow you to reach a
40:27final diagnosis by the mesothelioma or
40:29metastatic cost. Sonoma lymphoma etc.
40:31And of course you would need to
40:33do some primary.
40:34Organ site investigation in terms
40:37of adenocarcinomas, which is,
40:39you know,
40:40not something that you can do for
40:42melanomas or small cell carcinoma
40:46or squamous customers.
40:48So final case then discussions case
40:50number 6 the 45 year old female with ascites,
40:5435 mil of bloodstained fluid and
40:57of course you know I'm sure this
40:59is a spot diagnosis.
41:01For those of you with experience in.
41:04Cyto pathology we have got large three
41:09dimensional variable sized cohesive
41:11clusters of the malignant epithelioid cells,
41:16displaying course abundant
41:19cytoplasmic vacuolation nuclear
41:22hyperchromasia irregularity,
41:23high NC ratio,
41:26and variation of the nucleus size
41:28and shape from one group and
41:30one nucleus to the next,
41:31which is not a feature of
41:33mesothelioma as I said.
41:34Earlier.
41:35And again on the games are you
41:37have the same features the large
41:40groups tightly cohesive,
41:42no gaps or windows,
41:44unlike me, they feel proliferations,
41:47and these may be infiltrated by
41:49lymphocytes and and neutrophils.
41:52But then. In the background,
41:55you still have some uh lymphocytes,
42:00A4 size comparison. Once you do,
42:03your cell block or your plot section,
42:04you will be able to appreciate the
42:07microarchitecture of these groups as
42:09well with little glandular formations.
42:10Or perhaps some signet ring cells.
42:13And once you do your TTF one
42:15stain and it comes back positive,
42:18you have confirmation of metastatic cost
42:21Sonoma adenocarcinoma from the lung.
42:24And so this isn't an ever growing
42:27list of site specific markers.
42:32And you know,
42:33this is again constantly renewed and updated
42:36as some of the older markers become.
42:39You know less favorable because
42:41there are increasing numbers of
42:43studies that show that they're not
42:45particularly specific to those sites,
42:46and as new emerging markers turn up,
42:50but this is a sort of a rough guide
42:53to ascertaining the primaries
42:55with adenocarcinomas,
42:55and so a sample report for such a case is,
43:00again as follows.
43:01You gave your description.
43:02You assign it to the
43:04malignant secondary category,
43:05and then you perform your immunostains
43:08to ascertain the primary site.
43:10So my last couple of slides,
43:11diagnostic categories linking to
43:13clinical management once on the
43:16routine preparations and stains you
43:18make final call of nondiagnostic.
43:21Then of course you would ask
43:23for a repeat sample,
43:24ideally 50 to 75 mil if it is a
43:28negative for malignancy sample then the
43:31patient might be discharged or simply.
43:33Clinically followed up if it is in the
43:36Gray zone of a tipiya and suspicious,
43:38you need your ancillary work up and
43:41correlation with biopsy and clinical
43:43data to try and push as many of
43:45the atypical into negative and as
43:48many of suspicious into malignant.
43:49Of course,
43:50for the malignant category you would
43:52be performing ancillary testing,
43:54not necessarily to confirm malignancy,
43:57but to establish the primary site
44:00of origin and also prognostic
44:02and predictive markers.
44:04Just as the you know,
44:06manuscript last year was
44:07about to go to the publishers,
44:09I came across this a great article by
44:12Doctor Farahani and Doctor Bellotte
44:15in diagnostic psychopathology,
44:16the journal and they looked at the
44:19historic data before the publication of
44:22the Serious of Fluids Phytopathology book,
44:25of course,
44:26which looked at the risk of
44:29malignancy across the different
44:31diagnostic categories as reported.
44:34In literature Pre TS and what was
44:37noticeable was how high the risk
44:41of malignancy was in the atypical
44:44category and that is probably
44:46because there is a big overlap
44:49between the atypical and suspicious
44:51categories and with the application
44:54of appropriate criteria.
44:55Perhaps the risk of malignancy in
44:57this category will move closer
44:59to that of the negative and that
45:01or the suspicious category would
45:03move closer to malignancy.
45:05And this separation of the risk of
45:08malignancy between the different
45:10categories is the basis for the
45:13justification of any reporting
45:15terminology system, be it the faster Milan,
45:17Paris or the international systems and.
45:20And so this really is the data that I
45:23would be hoping that you will be
45:26collecting through auditing your cases
45:29prospectively and retrospectively to
45:31see you know before and after that.
45:35Number of cases and the risk of
45:38malignancy that you put into the
45:40uh into into the reporting system.
45:43So with that I thank you.
45:45I am going to stop sharing my screen
45:48and I am available to take any.
45:52Questions or comments from the audience?
45:54Thank you so much.
45:55Thank you so much Ashish is.
45:58Wonderful, I really like it.
46:00It's many, many questions in
46:02my mind has been addressed,
46:04so while the people are preparing their
46:07question so maybe I can ask you too.
46:09Small question. Actually one of them.
46:12It's related to your last page,
46:15so the the risk of malignancy.
46:19The risk of malignancy in
46:21negative for malignancy category.
46:23According to my manager Palaj if about 20%.
46:30Well, he was 20% meaning if
46:33we say negative malignancy,
46:35one in every five we are wrong.
46:38So what in your mind, this, uh,
46:40for this negative mallegni should be?
46:43Absolutely, that that's a great question.
46:45Peter and I think what we have looked
46:48at in that table is the historic data
46:52of how we have over the last 50 years,
46:56reported serious fluid cyto pathology and
46:59what the clinical outcomes of these cases
47:02have been if we but we don't know what
47:05the sample volumes of these cases were,
47:08we don't know whether they would have
47:11fulfilled the the sort of site, the.
47:15The criteria for good cellular
47:19preservation and celularity,
47:21as suggested by the international
47:22system so we don't have that
47:25data in this reported literature,
47:27and that I hope, will be the strength
47:29of the system going forward.
47:30Once we link this risk of malignancy
47:34to volume and to sell content,
47:36we might have a clearer picture to
47:38be able to say to our clinicians.
47:39Well, if you send us a 5 mil sample,
47:42the risk of malignancy could be considerably.
47:45Different to when you send
47:46us a 50 to 75 mill sample,
47:48but the problem there is of course that,
47:51uh, the follow up of patients with
47:54negative cytology is typically very
47:56difficult across all terminology systems.
47:59Whether it's urine,
48:01cytology or FNA,
48:02cytology the patients who have any fusion
48:05that resolves do not have any Histology,
48:08may not have much clinical follow up,
48:10and so you're left with this kind
48:12of no follow up of these cases.
48:15Or this kind of imagined follow up
48:16that we show that they were all
48:18right because they didn't come back
48:20to us with malignancy in the next.
48:22You know, two or three years,
48:23so we need to agree to certain
48:26surrogate markers and goal posts
48:27and we don't know what those are in
48:30terms of the negative categories.
48:32So that's a great question in terms
48:34of calculating the sensitivity
48:36and the negative predictive value
48:38over serious fluid sample.
48:40We don't really have great data,
48:42but I suspect it would be linked to volume.
48:45And a sample quality.
48:47Thank you for a great question,
48:48Peter,
48:49thank you. Thank you so much.
48:51Uh, another question from my end.
48:55Is that special staying for P16 so.
48:59P-16 you agree with a fish analysis
49:03kind of fish usually is pretty
49:06challenging for cytology sample
49:09and many people like immunostains.
49:12And I see this debating like animal Stampede.
49:1616 How you know how useful?
49:18How placable was your position here?
49:22So thank you. Another great question.
49:24Very very specialist and technical.
49:29I have to say the published data really
49:33mostly supports using P-16 mutation,
49:39you know, so we're not talking
49:41about the wild type P-16.
49:42We're talking about the mutated
49:44P-16 demonstrated by fish.
49:46So if you're using the appropriate
49:49immuno chemistry, of course not.
49:50For the wild type P-16,
49:52but for for the mutated one you
49:56should get you know good data.
49:59And I think that is something that
50:01we want to see more work done on
50:04before it can be accepted as a
50:07recommended clinical practice.
50:08You're absolutely right,
50:09there is a growing body of evidence
50:12and data that is suggesting that we
50:14could perhaps just do immuno chemistry
50:16rather than fish and that would solve
50:18a big problem because as you say,
50:20access to cytogenetics and fish
50:23is not easy for all laboratories.
50:26You know we're lucky to work in
50:28institutions where we do have.
50:30As to genetics and ancillary tests,
50:32uh, but you know,
50:34we these international terminology
50:36systems are meant to be used by the
50:40global psychopathology community,
50:41and if we set our benchmark,
50:43which is unachievable,
50:44then the project sort of loses its
50:46value because we've set the bar so
50:48high that it is completely unachievable by,
50:51you know,
50:51by the vast majority of our
50:54colleagues practicing cyto pathology.
50:56So I think we do have to be realistic,
50:58I think.
51:00Using that and that's why I emphasized
51:03so much the use of you know commonly
51:06used immunochemical immuno histo and
51:09cytochemical panels that include
51:12desmin and epithelial membrane antigen
51:14and bap one which it is easier for a
51:18smaller psychopathology laboratory
51:20to standardize and validate and
51:23be able to perform reproducibly
51:25and accurately within their own
51:27laboratory or at least have access.
51:30To the immunostains,
51:31but I know there are parts of the
51:33world where, uh,
51:34the diagnosis of MISO?
51:35Thi Lio Ma actually is just based on
51:38cyto morphology and perhaps some immuno
51:41cytochemical stains like oil red O
51:43positive iti in in in in mesothelioma.
51:46And that was a great point that
51:49Professor Claire Michael who's the
51:50lead chapter also for me the helium
51:52appointed out and she said you
51:54know we should try and find good
51:57cheap and easy stains for you know,
52:00mesothelioma.
52:00Because not everybody will have
52:03access to cytogenetics and to even
52:06immuno chemistry and to you know some
52:09colleagues practicing in constrained
52:12resources just histochemistry with
52:14oil red O and some other immunity
52:16and some other stains could be very
52:19very beneficial in the context of
52:21a good strong clinical suspicion
52:23of a mesothelioma for instance.
52:25So thank you for bringing up
52:27that very pertinent question.
52:29Thank you, thank you thank
52:30I have a question. Copying.
52:37OK, can you hear me now?
52:39Yeah yeah OK alright
52:44thanks for your great this great talk so.
52:49So based on this you know that international
52:53reporting systems and since we know,
52:57recommend the volume of the
53:00specimen is you know 75.
53:05Uh CC, which is you know,
53:07largely based on the.
53:10The Hopkins study recommended.
53:13But there's other study out
53:15there in the literatures.
53:16They actually recommend larger variance,
53:19you know, talk about 200 or 250 miles,
53:23and you know in in the age now is
53:28proficient precision medicines.
53:31You know a lot this specimen.
53:32Not only you know,
53:34Rick required health diagnostic work
53:37up also for the answering tests which
53:40may guide clinical management patient.
53:43So I just wonder,
53:44you know for this kind of system out there,
53:47you kind of flat out recommended you
53:50know 75 mil specimen weather you know.
53:55You know whether you're consider
53:57you know whether this you know,
54:00particularly in the setting of the,
54:02you know malignancy and weather,
54:05has any room.
54:06You know I, because the the the the one.
54:11The issue would be,
54:12you know clinical thing and look at
54:15the old you are you even you are
54:17report you are sitting recommended
54:19only 75 and mail you know specimen.
54:22So that's one one of my question.
54:24The other question I had.
54:26One day I notice,
54:27you know,
54:27in this system you don't have a
54:30category you know call for new problem,
54:33which many other system has this category
54:36robust sister you know Milan and you know,
54:40PSC, you know,
54:41and because particularly you talk about
54:44one the sample you you talk about in your,
54:48you know presentation is.
54:50You know pseudo makes Soma,
54:53which you know you ****.
54:56Basically you see them using or
54:59missing like material without without,
55:01you know,
55:02without absolute component you put in the
55:05category called suspicious for malignancy.
55:07The same issue will be also raised
55:11for like a borderline tumors and
55:13which also shows this kind of you
55:17know sales or material in your.
55:21Uh, and aside, is opera Tonio you know,
55:23public watch specimen?
55:25So, because this particular category
55:27is switched from Milligan and carry,
55:29the risk is about 80%,
55:32so I don't know how this will
55:34have any clinical impact.
55:35How you do on clinic,
55:37because basically there's no surgical
55:39diagnosis clad out malignancy,
55:41but you called speech for Magnus.
55:44Thank you.
55:45Yeah,
55:46great questions.
55:46I'll try and be brief in the
55:48interest of time, but I acknowledge.
55:50The limitations of the data that we
55:54have at the moment at the time of
55:58publication of the first edition,
55:59but what it has done is opened up
56:02this conversation that we're having
56:05today and which is what I was
56:08asked at the European Congress of
56:10Psychology in in Poland just last
56:12week where we had a whole session
56:15devoted to a tipiya versus NEO
56:17plasm in serious effusion cytology.
56:19Well seriously, in.
56:20All specimen doubts,
56:21but also addressing serious fluids,
56:24and that's a great question about
56:26taking your second question first,
56:27and I'll go back to the first
56:29time in a moment.
56:31So the new plasm category for fluids
56:34is is quite a tricky one to use.
56:37It will be very rarely used and
56:39in the kind of scenarios where
56:41you pointed out you know you've
56:42got mucinous material and you
56:44know it could be a NEO plasm,
56:46which may or may not be malignant,
56:47and so you know should that
56:49go into the tipiya category.
56:51Should that go into suspicious category,
56:52should that be in a NEO plasm category,
56:55I think at the moment what
56:57we are suggesting is that we
56:59put the query new plasm.
57:01The bland neoplasms including the
57:03borderline tumors into the atropia of
57:06undetermined significance category.
57:08So that is your sort of surrogate
57:11new plasm category for the moment.
57:13Let's see by the time of the second edition,
57:16in four or five years,
57:17if there is enough data out there
57:20to justify having an additional
57:23NEO plasm category.
57:25In addition to ATYPIA,
57:26we would be very much prepared to
57:28consider it. So that is a great question.
57:31But it wasn't something that we
57:34had enough data on to be able
57:36to address in the first issue.
57:38In the first edition,
57:39and so we have actually just put them
57:42or suggest that we put those under tipiya,
57:44but the discussion that we had in
57:47Poland was that a tip here actually
57:49includes the kind of cases which
57:52probably sit better in a NEO plasm category.
57:55Also, for instance,
57:57benign music Thielen preparations,
57:58though well differentiated papillary miso?
58:01Thi lio ma.
58:02Or the localized musically OMERS,
58:04which are essentially benign tumors?
58:06Should they all be called miso?
58:08Thi Lio Ma's,
58:09where do you know a typical or benign
58:12mesothelial proliferations go in the system,
58:15so those were all questions
58:17that are now being raised,
58:18and we hope that we will have
58:21more data in in the next few
58:24years to be able to answer that.
58:26Going back to your first question in
58:28terms of volumes of recommended sample.
58:31Again at the time of publication,
58:33we had a good study which you know
58:35was based on a very large sample size,
58:38and so we've gone with it.
58:40And since the publication of
58:42the international system,
58:43and even while it was in publication,
58:45there was a whole flurry of
58:48articles that suggested different
58:49volumes, some smaller volumes
58:51and some higher volumes,
58:52which in their institutional data was.
58:56A better marker for the sub you
58:59know for for the optimal volume,
59:01and I think there will be an institutional
59:04bias depending on whether you work in
59:07a Cancer Center or whether you work
59:09in a Community Hospital because your
59:11caseload is completely different.
59:14You're you know the sample volumes
59:16that you might get in a Cancer
59:18Center may be small volume samples,
59:21but they're all almost positive samples,
59:23so you know that they're not being
59:25sent to you for making a diagnosis.
59:27You already know the diagnosis they're
59:29actually sending you the sample just
59:31for the ancillary World Cup and as long
59:33as the sample is high in cell content,
59:35it doesn't matter whether it is 50
59:37mil or it's 75 mil or it's 200 mil.
59:40So the 75 mil optimal volume sample
59:43was really based on that curve which
59:46showed that once you have reached
59:49the 50 to 75 mil mark after that,
59:52there is no particular advantage
59:54because if the sample is negative.
59:57It is probably going to be negative,
59:58even if it's 200 mill.
60:00That is where you know that data came from,
01:00:03but the converse is also true.
01:00:05You might, you know,
01:00:08have a sample that's really really
01:00:10cellular and rich in malignant cells,
01:00:12for which you could get away with
01:00:14a much smaller sample.
01:00:15So I think the it's opened up
01:00:18a conversation around volumes
01:00:19around cell content,
01:00:21and I think there is quite a lot of work to
01:00:24be done before the 2nd edition comes out,
01:00:26but they're all.
01:00:27Things that I'm taking on board
01:00:28from our discussion today.
01:00:30So thank you very,
01:00:31very much.
01:00:32Thank you, thank you,
01:00:34uh, any more questions.
01:00:38So send I think Doctor Lu will
01:00:40have a separate zoom meeting, yes.
01:00:45So thank you so much, Ashish.
01:00:46So it's very nice to meet you and like
01:00:49you say we have so many discussions.
01:00:52Kind of good discussion and we're
01:00:54looking forward to your second edition.
01:00:57Thank you so much.
01:00:58Thank you very much.
01:00:59It's been a great honor and
01:01:01privilege to be able to talk
01:01:02to you this afternoon.
01:01:03Many Many thanks again for inviting me.
01:01:06Thank you, thank you.