Hypereosinophilia: Evolving Our Strategy

May 09, 2022

Information

May 5, 2022

Yale Pathology Grand Rounds

Kaaren Reichard, MD

ID7810

To CiteDCA Citation Guide

00:00So it's my great pleasure to
00:03introduce Doctor Khari Richard from
00:05our Yale pathology grand rounds.
00:07Dr Reichart study molecular biology at
00:10Princeton University and Medicine at Tufts,
00:13where she graduated with a OA distinction.
00:16She completed her AP and CP Residency,
00:19and also her Empath Fellowship at UT
00:22Southwestern and after a surge Path
00:24fellowship at Stanford University,
00:26she began as assistant professor
00:28at the University of New Mexico.
00:31Where she later served as chief
00:33of their Heat Path division,
00:35Doctor Richard was subsequently recruited
00:38to Mayo Clinic in Minnesota in 2011
00:41as their director of Flow Cytometry
00:43and also as their fellowship director.
00:45She became professor of lab medicine
00:48and pathology at Mayo in 2018 and
00:50is currently serving as their Chair
00:52of Education Oversight committee
00:54in the Division of Heme Path,
00:56which she formed over a decade ago.
01:00Doctor reichardt.
01:00Research focus is in the clinical,
01:03pathologic,
01:03and genetic features of myeloid disorders,
01:06and in particular in diseases
01:08that are associated with eastern
01:10affilia and mastocytosis.
01:12Her work has not only shed light
01:14in the pathophysiology of these
01:16difficult to diagnose tumors,
01:17but also demonstrated practical
01:19ways that pathologists can improve
01:21test utilization in their work up.
01:24She's authored over 100 book chapters
01:26and empath and is also coauthor of our
01:29beloved bone marrow pathology textbook.
01:31With Kathy Fuccaro and David Cholesky,
01:34innumerable trainees and junior
01:35faculty now all over the country,
01:37some of whom I know have
01:39flourished under her mentorship,
01:41and so if you have much to learn from her.
01:43In that regard, Dr.
01:45Walker has been an invited
01:47speaker for impactful courses,
01:48including those given a national
01:50meetings of CAP ASCAP and use CAP.
01:53So we are greatly honored by her
01:55visit today and for her talk on
01:58hypereosinophilia evolving our strategy.
02:00Thank you.
02:14Can you see my screen?
02:17Yes, perfect great.
02:18Well thank you so much good afternoon
02:22everyone and thank you Doctor Chu for that.
02:25Very gracious introduction.
02:26It's a great honor for me to receive
02:29this invitation from from you and
02:32I'm very grateful and pleased
02:34to have this opportunity today.
02:36I'd also like to thank the faculty
02:38and the resident fellow that I was
02:40able to chat with this morning.
02:41I learned a lot about your institution.
02:44It was just an absolute pleasure.
02:46And while it's unfortunate that I
02:48cannot be there today in person,
02:50it's still wonderful for me
02:53to be here virtually.
02:55As I was thinking about a
02:57topic for this presentation,
02:58I wanted to select something that
03:00was both somewhat broadly appealing,
03:02yet you also unique and one in
03:05which recent advances are pushing
03:07our boundaries of diagnosis.
03:09So I decided on hypereosinophilic
03:11conditions because our knowledge of
03:14these disorders as many of you know,
03:16has greatly expanded in literally
03:18just the past decade,
03:20and many of these advances have been
03:22incorporated into our current classification.
03:25System much of these advances are
03:27due to the molecular genetics space,
03:30which we will talk about,
03:32and because of these advances we
03:34are having to continually revise
03:37and evolve our strategy in how our
03:40diagnosis occurs in these conditions.
03:42I personally find that these disorders
03:45can be very tricky to diagnose and
03:47they can be somewhat overwhelming,
03:49and since one of the ways we learn
03:52as pathologists is by showing
03:55cases and studying.
03:56Cases you will see that I have
03:59interspersed case presentations
04:00throughout today's talk to illustrate
04:02some of the concepts that we will cover.
04:07I have nothing to disclose.
04:11So there are three learning
04:13objectives for today,
04:13two of which focus on the genetics
04:16of primary clonal ES and affiliate
04:19conditions over the past decade.
04:20As I mentioned, it has become clear
04:23that there are demonstrable recurring
04:26genetic abnormalities that underlie a
04:28distinct subset of these disorders.
04:31And these specific abnormalities,
04:33as I mentioned, are currently housed
04:36in our WHO classification system.
04:38So as we have walked this journey
04:41of discovering recurrent genetic
04:43abnormalities and ESN affilia,
04:45it is now becoming clear that there are
04:47new and additional emerging potential
04:50recurring genetic abnormalities.
04:52And I will mention them later
04:54in my talk as well.
04:55Thirdly, even though hypereosinophilic
04:57states are uncommon,
04:59they're very it's very unusual
05:01for them to come across our desk.
05:03As you will see,
05:05there is a vast array of ancillary
05:07testing that can be done in such cases,
05:09and because that can become quite costly
05:13and in that cost can incur quite quickly,
05:16I'm going to introduce a judicious
05:19yet comprehensive algorithmic approach
05:21to ESPN affiliate conditions.
05:25So what are hypereosinophilic conditions?
05:27These are disorders that are defined as
05:30disorders of diverse ideology and they can
05:33be clonal or non clonal and essentially
05:36there is a sustained overproduction of
05:38the acidophiles in these conditions.
05:41Why is it important to recognize?
05:43Because one of the most dire consequences
05:46of hypereosinophilic states is
05:48what is called Hypereosinophilic
05:50syndrome that results in significant
05:53patient morbidity and mortality.
05:55Due to the end organ damage that's
05:58caused by the ESMA Philic infiltrate.
06:02The concept of Hypereosinophilic syndrome,
06:04abbreviated HES and in fact the term
06:08itself HES has its origin in this 1968
06:12publication by doctors Hardy and Anderson.
06:15In this paper,
06:16they report three patients that had H ES,
06:20all of whom had extensive
06:22systemic involvement,
06:23two of whom even died.
06:25Based on their findings,
06:27these authors propose the term that
06:30we still use today Hypereosinophilic
06:33syndrome to emphasize that HHS is
06:36actually a continuum of disease that
06:38can range anywhere from an asymptomatic
06:41type of form to a rapidly fatal form.
06:46Seven years after doctors,
06:48Harding Anderson published their paper.
06:51She used it. It all published a much larger
06:53study of Hypereosinophilic syndrome.
06:55They reported on the clinical pathologic
06:58features of 14 patients with HS and they
07:02showed that the disease presentation was
07:04heterogeneous and quite variable with
07:07respect to the number and the type of
07:10organ systems that could be involved.
07:12They also reported that individuals that
07:15have cardiac or central nervous system
07:19involvement had particularly dismal outcomes,
07:22and they documented finally that
07:25most treatments are ineffective.
07:27Remarkably, their findings that
07:30they reported in 1975 capture much
07:34of what we still know today about
07:37Hypereosinophilic syndrome.
07:39Also of note and very interesting
07:41is that our modern definition,
07:43which I'll get to in a minute
07:46of Hypereosinophilic syndrome,
07:47is a vestige of their proposed
07:50diagnostic criteria in 1975,
07:53namely that you had to have an
07:55absolute acidophil count of greater
07:57than 1.5 * 10 to the 9th per liter.
08:01In their paper they had proposed
08:03that this was a persistent and
08:05sustained for at least six months.
08:08But we don't typically embrace
08:10the six month mark any longer,
08:12and that's for largely 2 reasons.
08:14One is,
08:15if patients have hypereosinophilia
08:17and we want to get them on treatment
08:19so that we can minimize any end
08:22organ damage that they may incur,
08:24and it's also because we have much
08:26more sophisticated tools to rapidly
08:28demonstrate that they are indeed clonal.
08:32So Fast forward to 2012 and this is our
08:34modern definition of hypereosinophilia.
08:37HE and Hypereosinophilic syndrome HES.
08:41Doctor Peter Violent and a group of
08:43experts in effect Affilia actually
08:45got together and they proposed
08:47common terminology and definitions
08:49for our US and affiliate disorders.
08:52Why so one of the major goals of this
08:55consensus paper was to enable us,
08:58as pathologists as clinicians,
09:00as laboratorians,
09:01to be able to communicate clearly
09:03across the board about what type of
09:06specific ES and affiliate disorder
09:08that an individual patient may have.
09:11In this consensus statement,
09:13HYPEREOSINOPHILIA was defined as
09:16persistent eosinophilia greater
09:18than 1.5 * 10 to the 9th per liter,
09:20and as I just mentioned,
09:21that's a vestige of the chosen paper.
09:24This has to be typically on two
09:26separate occasions separated by
09:28at least a month and or you have
09:30to have tissue hypereosinophilia
09:32which is greater than 20%.
09:34Eosinophils in the tissue of
09:36interest or bone marrow as defined
09:38by a pathologist or a marked
09:40deposition of use and affiliate
09:42granules and proteins in the tissue.
09:45Hypereosinophilic syndrome,
09:45obviously you need to meet the
09:48definition of hypereosinophilia,
09:50but in addition you have to have
09:53demonstrable end organ damage
09:55or dysfunction that is directly
09:57attributable to the SNF infiltrate,
10:00so it cannot be due to some other
10:03sort of disease process that has
10:05to be directly to the essentials.
10:08As shown in this table,
10:09the causes of ESPN affiliate
10:11are incredibly diverse and is,
10:13for me is one of the things I get
10:15nervous about when I see a casadia
10:17cinephilia because it is in fact so diverse.
10:19This may be due to a primary clonal
10:22state which you can see on the far left
10:24secondary to an underlying neoplasm in
10:26which the Essen affilia is actually
10:29reactive as shown in the center.
10:31Or it can be secondary to an
10:34entirely non neoplastic condition.
10:36In clinical practice,
10:38the overwhelming majority of
10:40hypereosinophilic states that we encounter
10:42are by far due to the secondary varieties.
10:45So in the case on the far right
10:47of entirely non neoplastic
10:49conditions this can be an infection,
10:51an allergic disorder,
10:53hypersensitivity reaction,
10:54drug reaction,
10:55a rheumatologic disease,
10:57and autoimmune phenomena.
10:58So there's a quite hefty number of
11:00underlying conditions that really need
11:02to be evaluated and excluded when
11:05presented with a case of essential.
11:07Earlier.
11:09In the cases that have an
11:11underlying neoplasm,
11:11whereby the is an affiliate,
11:13is reactive, as many of you know,
11:15we see this in cases of T cell lymphomas,
11:18classical Hodgkin lymphoma.
11:19For sure we can see it in a subset of
11:23carcinomas as well as the lymphocytic
11:25variant of Hypereosinophilic syndrome.
11:27As for the primary clonal Essen affiliates,
11:31these are of course less common,
11:33but as you can see from the
11:35less left side of the table,
11:37the diagnostic possibilities.
11:38Usually the one we consider first is
11:41chronically is cinephilic leukemia
11:43not otherwise specified and we have
11:46the new recently introduced WHO
11:49category of myeloid slash lymphoid
11:51neoplasms with ease and ophilia and a
11:56rearrangement of PDGFRA PDGFRB
11:58FGFR one and or Jack two.
12:01You can also see occasional
12:03cases of acute myeloid leukemia
12:05AML that can have Essen affilia,
12:07namely inversion 16.
12:08As well as a handful of other
12:11chronic myeloid disorders.
12:15So based on the diversity of causes
12:17of the oscillant theus and affiliate,
12:19this then naturally leads to a broad array.
12:22As I mentioned in the introduction
12:24of diagnostic testing options.
12:26As you can see on this slide,
12:28this is pretty chaotic,
12:29right that they are all over the map.
12:31They range from morphology
12:33to immunohistochemistry,
12:34to flow to cytogenetics to fish to next
12:38generation sequencing for myeloid disorder,
12:40associated genetic mutations.
12:42So the situation with the.
12:44Julia becomes very complicated,
12:46complicated and complex,
12:48pretty quick, and the question
12:50is what tests do we start with?
12:52Do I do them all or do I just do a subset?
12:57So as you can see from the number
13:00of references listed on this slide,
13:03many investigators advocate in
13:052022 for a systematic approach
13:07to the work of ES and AFFILIA.
13:10Most will agree that this is
13:12a reasonable starting point.
13:14Step one, exclude secondary causes.
13:17And of course this is very,
13:19very difficult to do because
13:20it generally in invokes a lot
13:23of different subspecialties.
13:24A lot of different testing
13:26that has to be done.
13:27But this you want to try and
13:29do this because you don't want
13:31to unnecessarily subject your
13:33patient to a bone marrow biopsy.
13:35If the patient is deemed to
13:37not have a demonstrable,
13:39determined reactive cause for the SN affilia,
13:44then we move to Step 2 and this
13:46is where the clinician has deemed
13:49it necessary for the pathologist
13:51to exclude a primary peripheral
13:53blood and bone marrow clonal
13:56process for us as pathologist.
13:58This is an extremely important
14:00step in the process because the
14:03prognosis differ hugely between these.
14:05Entities and several.
14:06As you will hear,
14:07have very specific targeted therapies.
14:10For example,
14:11rearrangements that involve
14:12PDGFR alpha or PDGFR beta are
14:15exquisitely sensitive to tyrosine
14:18kinase inhibitor therapy,
14:20so we're not going to want to
14:21miss a lesion like that that
14:23maybe the patient does not have
14:25to undergo chemotherapy.
14:27Step #3 is you've ruled out all
14:29the primary clonal disorders.
14:31You don't see an underlying T cell lymphoma.
14:33Reactive cause is not readily discernible.
14:37The specific diagnosis can't be rendered in.
14:39In most situations,
14:40we're going to sign out the
14:42bone marrow descriptively,
14:43and specifically mention which
14:45diseases we were able to exclude.
14:50So this slide expands upon the quote
14:52three steps that I just talked
14:54about and shows a more granular and
14:56algorithmic approach to the work up of
14:59sustained unexplained Essen affilia.
15:01The entry point into this algorithm is
15:04after step one has theoretically been done.
15:08So again, that is going to be.
15:09Oftentimes it's a multidisciplinary
15:11set of clinicians they've done a lot
15:14of testing to exclude infection,
15:15drug autoimmune rheumatologic disorders,
15:19etcetera.
15:20If at this point the patient is
15:22clinically stable so they're not sick
15:24from Hypereosinophilic syndrome,
15:26many of us would advocate beginning
15:28by assessing the peripheral blood
15:30and bone marrow morphology for peak.
15:32For features that point us to a specific
15:35entity, as shown by the blue arrow.
15:36So what do I mean by that?
15:38So if you look in the bone
15:39marrow or the peripheral blood,
15:41and you see features, oh,
15:42this might be mastocytosis.
15:43Or this might be a specific type of myeloid
15:46neoplasm such as chronic myeloid leukemia,
15:48or you see lymphoma, then.
15:50If that's the case.
15:51Then we would start by doing a very
15:54targeted work up rather than the very
15:56broad and affilia type of approach.
16:01So here's an example of this in in real life.
16:04This patient was a 48 year old woman.
16:06She presented to her primary care
16:08physician with left Upper Quadrant Pain.
16:10They did a CBC and you can see those showed
16:13this whopping Leukocytosis with a greater
16:15than 100,000 white blood cell count.
16:18The peripheral blood,
16:18which I've shown you a snapshot on the left,
16:21definitely shows increased esena
16:22filters at least five in this field,
16:25and when you have a white count of 100,000,
16:27it's pretty obvious that you're going to meet
16:30the diagnostic criteria for Edison affiliate.
16:32However, in addition to the essentials,
16:35what do we see?
16:37We also see a granulocytic left shift.
16:39No dysplasia and increased basophils.
16:43When you look in the bone marrow aspirate
16:45smear which is shown in the center,
16:46what do we see? We see.
16:47It's hypercellular.
16:48There's a granulocytic predominance
16:50and look at those megakaryocytes.
16:53They're small.
16:53They're monologue eated.
16:55We have dwarf forms,
16:56so we're getting a little suspicious
16:58that we might be dealing with
17:00something specific on the far right
17:02you see the bone marrow core biopsy.
17:04It's basically packed 100% cellular
17:07granulocytic predominance.
17:08I mean the any ratio has got to
17:10be greater than 12:50 and you
17:11can see those small monologue.
17:13Get into dwarf megakaryocytes.
17:15So in this particular situation,
17:18do we have eosinophilia?
17:19Yes,
17:20but we have other features that might be
17:22suggesting what chronic myeloid leukemia.
17:24So rather than me doing all as
17:27I'm going to go through later,
17:29all the ES and affiliate related testing,
17:31we would probably start with a targeted
17:33work up looking for chromosomes
17:35at for Philadelphia chromosome
17:37and doing fish or molecular for
17:39the BCR ABL 1 fusion protein.
17:41And in fact that's what we did and we
17:44diagnosed this case as CML BCR ABL.
17:45And positive chronic phase.
17:47So in the context of this case,
17:50the ESCENA affiliate is technically present,
17:53but it exists merely because of the
17:56context of the overall disease.
17:58It's not its own distinct clonal
18:02theosophic disorder.
18:03OK,
18:04So what do we do in a situation
18:05where I don't see features that
18:07suggest a particular disorder?
18:08It's not mass cells.
18:09It's not lymphoma.
18:10Well based on the differential
18:13diagnostic possibilities that
18:14I mentioned mentioned back on.
18:17On the potential causes of
18:18primary colors and affilia,
18:20this could be mass cell disease.
18:21It could be chronic and Phillip
18:23leukemia not otherwise specified.
18:24Maybe it's one of those new myeloid
18:27slash lymphoid neoplasms with ease and
18:29affilia and a recurring genetic abnormality.
18:32Maybe it has a subtle T cell clone.
18:34So based on studies that
18:36are in the literature,
18:37peer reviewed,
18:38published literature reasonable
18:40up front testing,
18:42which is highlighted by the
18:43the boxes with the Blue Star
18:45immunohistochemistry for mast cells,
18:47T cell flow cytometry tree
18:50looking for subtle ibara clones.
18:52Kit D816V mutation,
18:53which is seen in the overwhelming
18:55majority cases of mass cell disease,
18:57want to do chromosomes,
18:59you know,
18:59just general karyotyping and
19:01you're going to want to do
19:03fish for the PDGFR.
19:05Offer rearrangement.
19:06I would also suggest considering given
19:08how the complexity of the Ascent
19:10affiliate is going to continue to grow.
19:13Consider doing DNA and RNA extract and hold.
19:17So you may be wondering,
19:18well why am I going to do fish for the
19:20PDGFR alpha when you mentioned that there
19:22are four that are recognized by The Who?
19:24So the reason for that is that the PDGFR
19:27alpha rearrangement in greater than 80 to
19:2985% of cases is cytogenetically cryptic,
19:32so you won't see it by a
19:34routine chromosomal study,
19:35so we don't want to miss this
19:37diagnosis number one because we
19:38won't see it with chromosomes,
19:39but number two.
19:41As I mentioned it is exquisitely sensitive
19:43to tyrosine kinase inhibitor therapy,
19:45so you really have to do.
19:47Because some laboratories would do it by
19:49molecular up front for this abnormality.
19:52Depending on what this aggregate of
19:55ancillary studies shows or doesn't show,
19:58this is going to help inform us
20:00as to whether we can move towards
20:03a specific diagnosis.
20:04So here's an example of of what I mean.
20:06So this this is a 59 year old woman.
20:09She hasn't been feeling well for 15 years.
20:12Can you imagine?
20:1315 years foggy brain.
20:14She has like spills occasionally.
20:16She has some abdominal pain,
20:18but it's not really.
20:19You know, chronologically reproducible.
20:21No itching and then she has these occasional
20:25small red freckles on her bilateral shins.
20:28So of course you know she's going to
20:29go in through her primary care doc.
20:30She gets extensive testing.
20:32Infectious disease, autoimmune.
20:34Rheumatology, you know etcetera.
20:36Drugs medications.
20:38Everything is negative,
20:39so they do a CBC and you can see here.
20:41It's basically unremarkable.
20:43All the counts are normal except
20:45the absolute east and a field
20:47count is 580 which is just over
20:49our upper range of normal of a 500.
20:51So we look at our peripheral blood smear
20:53and see if we see anything basically
20:56compatible with the CBC differential matches.
20:59There's a few mature EO,
21:00a few scattered monos and neutrophils.
21:02So pretty much boring.
21:05Bone marrow aspirate was also performed.
21:07Relatively unremarkable.
21:08There's intact trial and intimate voices.
21:11We have progressive maturation.
21:12We don't have an increase in blasts.
21:15We don't have lymphoma cells.
21:16We don't have an increase in monos.
21:17We have no dysplasia.
21:18We have no basophils and we have
21:21about 4% epinephelus and uphill.
21:23So you know not that impressive.
21:25We did.
21:26Also note,
21:26you know every now and then
21:27there were scattered mast cells,
21:29but you really had to hunt for
21:30them and for the most part they
21:32were round and relatively mature.
21:34But occasionally there was a.
21:35Single form. Bone marrow core biopsy.
21:39Again, completely unremarkable.
21:40Normal cellular for her age progressive
21:44intact normal trilineage hematopoiesis.
21:46No obvious bone abnormalities or no
21:49infiltrates, no granulomas etcetera.
21:53But because of the subtle increase
21:55in her peripheral eyes and ophilia
21:57and the history that the clinician
22:00told us of spells and these red
22:02freckles on her shins,
22:03we did deploy the algorithmic approach for
22:06eastern Affilia, which, as I mentioned,
22:09includes immunohistochemistry for mast cells.
22:11And as you can see here, I've shown
22:13it at two different magnifications.
22:15The tryptase stains highlight no.
22:17I don't know. It's a normal number.
22:19Maybe a slight increase in mass cells,
22:21but as you can appreciate a good proportion
22:24of them appear distinctly spindled.
22:27And while there's no focal compact
22:30dense aggregate formation which we
22:32would need according to The Who to meet
22:35major criterion for mass cell disease,
22:37there is this sort of subtle perivascular
22:40collection in the right image,
22:41as indicated by the blue arrow.
22:43So we are seeing a little, you know,
22:45while most of them are interstitial
22:47and individually distributed,
22:48there might be a subtle collection
22:50around the vessel as part of the workout.
22:53We also do a CD-25,
22:55and as you can see here on quite high power.
22:57There is aberrant positivity on
23:00the mast cells.
23:02Importantly,
23:02this aberrant expression can be
23:05difficult to assess on low power,
23:07so it's really imperative when
23:09you have a case like this,
23:10go to higher power to either appreciate
23:13positive or negative staining.
23:15Similarly,
23:15as in a case like this,
23:17given that the mast cells are
23:20interstitial and individually
23:21distributed without aggregates,
23:23it can be really hard to actually
23:25find the mast cells and be confident
23:27that they are indeed negative,
23:29and that makes the interpretation
23:31even trickier.
23:32So at this point in our patient we
23:35have abnormal spindled mast cells
23:37which Co Express aberrant CD 25,
23:39so we have two of the four minor
23:43criteria for SM for The Who.
23:45So as I mentioned,
23:47another part of the eosinophilia
23:49workup is to perform testing
23:50for the kit D816B mutation,
23:52and here in our institution we do an
23:55allele specific PCR assay that has
23:58an incredible sensitivity of 0.01%.
24:01So if we have a decent cellular,
24:03non hemo dilute aspirate,
24:05it is very likely that with the
24:07if the mutation is present that
24:09we will actually detect it even
24:11if we have very few mast cells.
24:13So we did the testing in this particular.
24:15Patient and you can see the positive
24:18signal for the presence of a kit D816.
24:21The mutation in the top image.
24:24If the mutation were absent,
24:26the top image would be devoid
24:28of a signal and the the signal
24:30that you're seeing on the bottom
24:32image is actually the wild type.
24:34In her particular case.
24:36So with this finding,
24:38we now have 3 minor criteria according
24:42to The Who we have aberrant CD 25
24:46expression we have spindled mast
24:48cells and we have a kit D8160.
24:51So in this particular case the
24:54the use and affiliate algorithm
24:56was important to deploy because
24:59as I hopefully have illustrated,
25:01massel infiltrates can be morphologically
25:04occult and inconspicuous,
25:05and you have to use your clinical.
25:07History to help you discern
25:09these types of cases,
25:10and importantly in this case,
25:12we were able to make a diagnosis
25:14that explained this.
25:15Patient's spells, foggy brain
25:17that she had had for 15 years.
25:22So if the mass cell workup is negative,
25:24which it oftentimes is,
25:25you're going to rely on the results of
25:27your cytogenetics and your fish testing.
25:29Depending on these results,
25:31the case is going to end up,
25:33typically in one of three diagnostic buckets.
25:37If there is positivity by chromosomes
25:39and or fish for one of The Who
25:42recurring genetic abnormalities
25:43associated with the existing affiliate,
25:46namely PDGFRA, PDGFRB FGFR One or Jack 2,
25:53then we would diagnose those
25:55neoplasms accordingly.
25:56Importantly, given that most cases
26:00of the non PDGFRA rearrangements
26:03are cytogenetically evident if you
26:06do get a chromosomal abnormality,
26:09AT-5232 or 8P11 that suggests ohh, PDGFR,
26:12beta or FGFR, one might be involved.
26:15You absolutely have to do fish or
26:18some other type of confirmatory
26:20testing to document that in that
26:22indeed that particular genetic
26:25locus is in fact rearranged.
26:27And the reason for this is not only
26:29because it's making the right diagnosis,
26:31but it also may dictate appropriate
26:34downstream therapeutic management.
26:38If the chromosome results demonstrate
26:40a myeloid disorder associated clonal
26:43abnormality, this would of course
26:45exclude trisomy 8 - y and deletion 20 Q.
26:48Then this could be used in the appropriate
26:51context as a diagnostic criterion to support
26:54a diagnosis of chronic geoscientific
26:56leukemia not otherwise specified.
26:58And finally, if you come up empty with fish,
27:02you come up empty with chromosomes,
27:03they're all normal.
27:05This indicates one of three
27:08diagnostic possibilities.
27:09Probably the most likely is it's
27:11a reactive heist and affiliate,
27:13for which we just haven't been able to
27:15figure out what the underlying cause is yet.
27:17It's possible it could be a case of
27:19true idiopathic hypereosinophilia,
27:21which I would say those are becoming less.
27:25Less common because we are now
27:28finding the genetic underpinnings
27:30of those particular entities.
27:32Or lastly,
27:32it could be a clonal ES and affiliate
27:34for which we haven't yet detected
27:36the genetic alteration, right?
27:37So if you're only doing you know
27:40fishing chromosomes and maybe a limited
27:42next generation sequencing panel,
27:43there's obviously still a whole host
27:45of the genome that may be abnormal.
27:48In my opinion,
27:49this is my personal opinion
27:50in these particular scenarios.
27:52I think it's really important to go
27:54back and do a global reassessment
27:55of all the facts in the case,
27:57how worried is my clinician that I'm
27:59dealing with a malignant disease process?
28:02Is it behaving in the patient
28:03as a as a neoplasm?
28:05How worried am I as a pathologist
28:07based on what I'm seeing?
28:09So part of us evolving our strategy in
28:12these cases is learning when we should
28:14continue to move forward and push forward.
28:17This genetic testing or RAC,
28:18whatever it happens to be
28:20and when we should hold.
28:22If there is sufficient clinical and or
28:25pathologic suspicion for a clonal disorder,
28:28additional testing either through next
28:30generation sequencing or RNA C should
28:33be considered as clinically indicated.
28:36Also importantly,
28:37at this step,
28:38if you're very worried as a clinician
28:40or pathologist and you've only done
28:42chromosomes to look for PDGFRB,
28:44FGFR, one,
28:45etcetera,
28:45I would actually consider doing fish at that
28:49point because we now know that even though,
28:51albeit small,
28:52number of cases.
28:54There are those cases that
28:55are cytogenetically cryptic,
28:56so again,
28:57as I mentioned before,
28:58because of prognostic and
29:00therapeutic implications,
29:01we would want to make sure we
29:03were definitively including
29:04or excluding those diagnoses.
29:08So I've mentioned a little bit
29:10about the myeloid slash lymphoid
29:12neoplasms with eosinophilia and the
29:15recurring genetic abnormalities,
29:16namely PDGFRA B, FGFR one and Jack two.
29:21As those are currently recognized by The Who.
29:24As you can see in this table,
29:25I've listed those four genes in that
29:27order along with their chromosomal
29:29location just for ease of reference
29:31and some of the translocation partners
29:33that have been reported to date.
29:36As you can appreciate these genes.
29:38And translocate with a variety
29:40of different partners.
29:41Indeed more.
29:42There's more than 30 partners that
29:44have been described to date for PDGFR,
29:47beta and more than 15 for FGFR one.
29:51I've also listed the most common
29:53translocation partners in front of the
29:55semi colon, just for ease of reference.
29:57So for example,
29:58FIP 1L1 is by far the most common
30:01partner with PDGFRA and I mentioned
30:04that 80 to 85% of those cases are
30:06cytogenetically cryptic and that is because.
30:08Partner FIP 1L1 is actually on 4212 as
30:12we'll see in see here in a little bit.
30:14Also you can see that ETV six is the
30:18most common partner with PDGFR beta.
30:22You'll also notice that after
30:23the Jack 2 Gene,
30:24I've also inserted two
30:26additional tyrosine kinases,
30:28FLIP 3 and Abel one,
30:30and the reason I've included these
30:32here is although they're not currently
30:34recognized by The Who as distinct
30:37clinical pathologic entities.
30:38They are emerging in the published
30:40literature as being associated with
30:42the cinephilia and having these
30:44recurring genetic abnormalities.
30:45So I think it's important to note
30:48that this list of genetics is
30:50only going to continue to grow.
30:52And lastly,
30:53on the very bottom there's also a
30:55handful of other non translocation
30:58events that have been reported
31:00recently that do associate as
31:02well with ESPN Ophilia.
31:03These include insertion,
31:04deletion events and Exxon 13 of Jack 2.
31:07The stat
31:105BN642H mutation and then,
31:12although not specific,
31:13a whole host of mutations
31:16in genes such as ASX 1 TET,
31:192 easy H2 and others.
31:21So again this list.
31:22The genetic findings in clonal
31:24east and affiliates just continues
31:26to grow and I would argue it's
31:28getting even more complicated and
31:30a consequence of this is that
31:32it forces us in somewhat of a
31:34good way to evolve our strategy
31:36with respect to how are we going
31:38to approach and work up these
31:40cases in 2022 and beyond with
31:42the ultimate goal of getting the
31:44right diagnosis but doing the
31:46right testing for our patients.
31:50Recognition of these recurring
31:52genetic abnormalities is important
31:53for a couple of reasons, and again,
31:56as I mentioned on the last slide,
31:57although rearrangements of
31:58flip three and able one,
32:00I've listed them out separately here.
32:02That's just, that's merely because that
32:04they're not recognized by The Who,
32:06but I've included them here
32:07because they share,
32:08as I will show you,
32:09many of the amazingly similar
32:12characteristics to the currently
32:15recognized WHO entities first,
32:17as you might expect based on the.
32:20WHO naming convention,
32:22these genetic alterations are typically
32:24associated with the US and OPHILIA.
32:27That's good for us as pathologist
32:29because it helps us be able to identify
32:31them and do the appropriate testing.
32:34Second,
32:34translocations involving these genes
32:36are notorious as I'll show you on the
32:40next slides for Multilineage involvement,
32:42so this can include a whole variety
32:44of chronic myeloid disorders.
32:46They may manifest as chronic yeast,
32:47and I feel like leukemia and OS.
32:49They may look like.
32:51Myelodysplastic myeloproliferative
32:52overlap syndrome.
32:53They may also present as
32:55an acute myeloid leukemia.
32:57They can also present as B&amp;T
32:59cell lymphoblastic leukemia,
33:00so it's pretty much all over the map,
33:02but if they have the S and
33:04affilia accompanying them,
33:05they can help us recognize them more readily.
33:09Third,
33:10there are significant
33:12therapeutic implications,
33:13depending on which of
33:14these genes are rearranged,
33:15as I've mentioned.
33:17Rearrangements of PDGFRA and
33:18B are exquisitely sensitive to
33:21tyrosine kinase inhibitors.
33:23However,
33:23rearrangements of FGFR one and
33:26Jack two are not.
33:28Therefore,
33:28in those situations that opens up
33:30the possibility for alternative
33:32therapies in those particular patients.
33:35Jack 2 inhibitors.
33:36Maybe a flip 3 inhibitor,
33:38maybe a small molecule you know
33:41that has that has a clinical trial,
33:43so this information is important
33:45for your clinical folks.
33:47Because they know how to treat
33:48the patients and whether to try
33:50to get them on a clinical trial.
33:54So this slide is busy,
33:55but I like it because it summarizes many
33:58of the clinical pathologic features
34:01of the four WHO recognized myeloid
34:04lymphoid neoplasms with ES and OPHILIA
34:07and a recurring genetic abnormality.
34:09I'm going to show you this same
34:12display of information for Flip 3
34:14and Abel one on the next slide so
34:16the genes are listed across the top
34:18in the first row of each column and
34:21the disease presentation the extra
34:23medullary tissue involvement and the
34:26association with hypereosinophilia
34:27are shown in the far left column.
34:30So helicopter view as you look
34:32across all of these four genes,
34:34you can appreciate that a heterogeneous
34:37presentation is very typical as I.
34:40You had mentioned previously the
34:42disease presentations and this can vary
34:45to some extent depending on what the
34:47what the recurring genetic abnormality is.
34:50Chronic isn't affiliate leukemia.
34:52Chronic myelomonocytic leukemia.
34:54Acute myeloid leukemia
34:55lymphoblastic leukemia,
34:56mass cell disease, and others.
34:58The plus signs that are next to the disease
35:02represents the relative proportion of
35:04cases within that diagnostic category
35:07that reportedly present as that particular.
35:10Type of disorder.
35:11So for example,
35:12the majority of cases with the PDGFR
35:16alpha rearrangement present as CEO,
35:18chronic use and affiliate leukemia.
35:20In contrast,
35:21most cases of PDGFR beta
35:24rearrangement present as a chronic
35:27myelomonocytic like picture.
35:30Another key take away from this
35:32table is the association with
35:34Extramedullary disease presentations.
35:36This is particularly true for FGFR 1.
35:40Rearranged cases in fact,
35:42FGFR 1 rearranged cases are
35:45notorious for a complex presentation.
35:48What do I mean by complex presentation?
35:50That basically means that the case will
35:53present as a chronic myeloid neoplasm,
35:56possibly with eosinophilia in the
35:57peripheral blood or bone marrow.
35:59But then it will have a lymphoblastic
36:01lymphoma or a myeloid sarcoma
36:03or a mixed phenotype.
36:04Acute chemia presentation
36:06in an extramedullary site.
36:09This is important because as
36:10you can see with the association
36:12percent with ESPN affiliate,
36:14it's only about 80% of cases that
36:17have these genetic rearrangements
36:18that have ESPN affiliate.
36:21So how am I going to diagnose it
36:22in the other 20% that don't have
36:24any S and affiliate,
36:25and that's where it really becomes tricky.
36:27So knowledge about these heterogeneous
36:29disease presentations as well as the
36:31complex presentations can really aid
36:33you as a pathologist to be thinking.
36:36Ooh,
36:36even though I've got a Tal and a lymph node.
36:39You know there's no use in affiliate,
36:40but I've got maybe a chronic myeloid
36:42in the bone marrow would prompt you
36:44to potentially consider testing for
36:46one of these genetic abnormalities.
36:50So just as I mentioned on the last slide,
36:52I think Eason I feel like
36:54disorders with recurrent genetic
36:56abnormalities is a is expanding.
36:58This includes rearrangements
36:59of foot three and Abel one.
37:01And as you can see they are amazingly
37:03similar to the ones that are
37:06currently recognized by The Who.
37:07They can have a heterogeneous
37:10disease presentation.
37:11They have a frequent but not 100%
37:13association with the US and AFFILIA,
37:16and they can have extramedullary
37:18disease involvement.
37:19Foot three rearranged cases.
37:21In particular,
37:22it's kind of easy to remember
37:24because it starts with F and FGFR.
37:25One starts with F.
37:26They are very similar in that they tend
37:29to present with a complex presentation,
37:31which again includes CEO or CEO
37:33like picture in the peripheral blood
37:36and T lymphoblastic lymphoma or
37:38a myeloid sarcoma in the tissue.
37:40Able one, rearranged cases,
37:41on the other hand,
37:43have much less of an
37:45extramedullary presentation,
37:46and the overwhelming majority present
37:48as a chronic myeloid disease.
37:49Typically CE L excuse me or an overlap.
37:52MDSM PN.
37:55So what do these cases
37:57look like in real life?
37:58Well, this case is classic and
38:00it's a nice one to see if you
38:02haven't had one come across your
38:04desk in in clinical practice,
38:06so this was a 35 year old male who
38:09presented with constitutional symptoms.
38:11CBC was done and it was noted that he had
38:14an absolutely essential count of 4500,
38:16so greater than the 1.5 times
38:18into the nine per liter.
38:20I've shown you a high power image of
38:22the peripheral blood and basically
38:24the majority of his ES NFL's
38:25were cytologically unremarkable.
38:27The bone marrow aspirates
38:28were specular and cellular.
38:30There was a lot to look at and
38:31basically we saw predominance.
38:33Escena Phils and Escena Phillip precursors.
38:36The core biopsy was markedly hypercellular,
38:39basically due to the increased
38:40via syphilis and precursors,
38:42and I wasn't able to appreciate any obvious.
38:44You know, mass selling fill trades,
38:46no lymphoma. There was no increased blast.
38:49The legs were predominantly unremarkable.
38:51But because it's a work up
38:53for ESPN affiliate,
38:53we did the IMMUNOSTAINS for mast cells
38:56and you can see here with the tryptase.
38:58We have very similar to what we saw before,
39:01but perhaps an increased
39:02number of mast cells increased,
39:04interstitially distributed
39:06spindly mast cells and they showed
39:09aberrant CD 25 expression.
39:11As you can see in the lower right image.
39:14This is very typical,
39:15but it's not exclusive of this
39:17disorder is the lack of a
39:20mass cell aggregate formation.
39:21In rare cases,
39:22it can actually form aggregates,
39:23but this type of pattern would be
39:25a clue that you might be dealing
39:28with this particular abnormality.
39:30We did do kit molecular testing
39:32for DNA 16B and it was negative,
39:34so that would essentially exclude not always,
39:37but essentially excludes mass cell disease.
39:41We also did as part of our algorithm fish
39:44for a PDGFR alpha gene rearrangement.
39:46Again, as I mentioned,
39:48because these are cytogenetically
39:50cryptic and 80% of those cases are
39:53because of the FIP 1L1 gene which is
39:56colocalized on 4Q12 with PDGFR alpha.
39:59So the 5th 1L1 PDGFR Alpha fusion is
40:03the consequence of an interstitial
40:06deletion on chromosome 4 Q 1/2 and
40:09a key component of this fusion
40:11is the loss of the chip 2 gene,
40:14which sits in between FIP one
40:17and PDGFR alpha,
40:18and I'm only mentioning this
40:20because on occasion you may hear
40:22this fish Pro panel referred to as
40:24to fish or chip 2 deletion fish.
40:26So just be aware that chip two
40:29really has nothing to do with.
40:31But it's just by default what people
40:33refer to this as in this particular assay,
40:36the normal.
40:37So like you and me,
40:38hopefully normal fish pattern
40:40is 2 fused triple signals,
40:42meaning the red Aqua in the green are
40:45all colocalized because they're all
40:47sitting right at that band on four Q 12.
40:50So as you can see on the chromosome
40:52image on the far right flip one is FIP,
40:541L1 is green chip,
40:55two is red,
40:56and PDGFR alpha is blue.
40:59So if you have an. Abnormal fip 1L1.
41:01PDGFR Alpha fusion the red probe
41:04is going to be lost, right?
41:06You have the interstitial
41:08deletion of chip two.
41:09And as you can see in this particular
41:11patient I've shown highlighted by the arrow,
41:14the fish assay is positive for a chip
41:17to deletion, AKA loss of the red signal.
41:21So the surrogate of that is that
41:24this manifests as a fifth one.
41:27L1 PDGFR alpha fusion.
41:29So in this particular case.
41:31You're actually able to make a diagnosis.
41:33This was our diagnosis.
41:35It's a chronic myeloid neoplasm with theists
41:38and affilia and a PDGFR alpha rearrangement,
41:41and the partners FIP 1L1.
41:43Typical features of this are just
41:45very nicely exemplified by this case.
41:48Almost all the patients are male.
41:50They actually present at a younger age,
41:52so in the 30s or 40s is not uncommon.
41:54They typically have peripherally
41:56as an affiliate,
41:57and they have those abnormal mass cells,
41:59those interstitial individually.
42:01Distributed mass cells that express CD-25,
42:03and they typically don't
42:05have an increase in blast.
42:06They don't have dysplasia, etcetera,
42:07so it's very typical presentation.
42:10Importantly,
42:10this fusion has significant
42:13not only diagnostic,
42:14but therapeutic implications.
42:15Because this is a target for
42:18tyrosine kinase inhibitors.
42:22OK, so with this next case I'm going
42:25to shift gears and I'm going to talk
42:27about the interface of idiopathic
42:29hypereosinophilia and chronic lymphocytic
42:32leukemia not otherwise specified.
42:34So this is a very interesting case.
42:37It came across my desk a couple of
42:39years ago and our institution patient
42:40was 61 years old and he was actually
42:43hospitalized because he was going to
42:45have a whipple for a tubulovillous
42:47adenoma in the head of the pancreas.
42:50So you know, obviously part of Presurgical
42:53workup was to do a CDC and they found this
42:56whopping absolutely as an affiliate account.
42:5820,000 was absolutely
42:59as an affiliate account,
43:01so the surgeons you know
43:01they kind of go well.
43:02That's kind of weird,
43:03and so then they decided to get
43:05a hematology consult just to see
43:07what that means or what they should
43:08do before the doing the whipple,
43:10so the hematologist determined that
43:12they needed to do a bone marrow biopsy.
43:15And along with that comes peripheral blood
43:18smear review so the peripheral blood smear,
43:20which I've shown here.
43:22The slide corroborated the massively
43:24increased and expanded number of eosinophils,
43:27and for the most part they were
43:29actually morphologically unremarkable.
43:30Some of them might have had
43:32a few cytoplasmic vacuoles,
43:33but they weren't distinctly hypo granular.
43:35They weren't hypersegmented.
43:36They were pretty boring, honestly.
43:39But here's the bone marrow aspirate
43:41definitely showed increased yeast
43:42in the fields.
43:43It was about 40% of nucleated cells.
43:46There was background intact,
43:49erythropoiesis background intact,
43:50ranial choices, no dysplasia,
43:52no increase in blast,
43:53no lymphoma, no increase in monos,
43:55but the megs which I'm showing you
43:57here with a couple of arrows they told
43:59to me they were telling a different story.
44:02I thought they were pretty abnormal,
44:04some of them were really small with
44:07these hyperchromatic condensed nuclei and
44:09others were very clearly small and monologue.
44:12So I was thinking about,
44:14you know what testing should I do?
44:15I know I have to follow the
44:17ESPN affiliate algorithm,
44:18but I was also really worried about
44:20other potential myeloid disorders.
44:22So I kind of broke from the S and
44:24AFFILIA algorithm a little bit.
44:26And this is what I ordered.
44:28I did carry a typing. It was normal.
44:30I did BCR ABL 1 fish and I did
44:33inversion 16 fish,
44:34which is the CBF beta MH 11.
44:37I looked for a rearrangement by fish
44:40for PDGFR alpha beta FGFR one and Jack two.
44:44I also looked for a myeloproliferative
44:47neoplasm driver mutation,
44:49so like Jack to ****** color.
44:51I did kit of course,
44:53just because that's part of the algorithm.
44:54Everything was normal flow cytometry.
44:56Is normal and I had no abnormal
44:58mast cells by immunohistochemistry,
45:01so it's not CML, it's not inversion 16.
45:04I'm not really getting a recurring
45:06genetic abnormality,
45:06so it's probably not one of those.
45:09I can't really call.
45:10Is it hydropathic hypereosinophilic?
45:11What is it?
45:12Is it CL Nos?
45:13Or am I just barking up the wrong
45:16tree and this is just an odd
45:18reaction to this underlying tubulo
45:20villous adenoma?
45:21So for me to make a diagnosis of
45:24idiopathic hypereosinophilia,
45:25basically that's a diagnosis of exclusion,
45:27so I'd have to exclude everything else.
45:29What about CEL and OS?
45:32So here are The Who criteria.
45:34There are five of them.
45:35The first four we had
45:37already checked the boxes.
45:38OK, so we have used an affiliate of
45:40excluded all these other myeloid disorders.
45:42I don't have a rearrangement
45:44that's recurring,
45:44and I know that my blasts are less than
45:4620% and I don't have inversion 16 or 822,
45:49but I didn't have criterion #5.
45:52I did not have a Colonel
45:54cytogenetic abnormality,
45:54and I did not have more
45:56than 2% blasts in blood,
45:57or more than 5% in the bone marrow.
46:00Even though I had hyperius and
46:02affiliate and abnormal appearing legs
46:04couldn't quite make the diagnosis.
46:06If I followed The Who strictly.
46:09So there is a reference in the 2017
46:11Blue book that you can use a molecular
46:15genetic abnormality to support clonality,
46:18but those in those cases you have to
46:20absolutely exclude that you're not
46:22dealing with chip clonal hematopoiesis
46:24of indeterminate potential.
46:25So for example if I had done
46:28next generation sequencing and I
46:30picked up a single mutation and.
46:31SX1 or Ted two or DNMT 3A.
46:34So the classic culprits of chip and
46:36it's at a reasonably low variant
46:38allele frequency that I wouldn't be
46:40able to use that as a as a diagnostic
46:42slam dunk criterion for clonal abnormality.
46:45So just exercise caution if you're going
46:47to go the next generation sequencing route.
46:50So what do we know about NGS
46:52in this particular scenario?
46:54So I tried to summarize on the literature
46:55that I was able to find about NGS
46:57and the ascent affiliates pretty limited.
46:59As you can see,
47:01but we knew know that from
47:03several of these studies,
47:04myeloid disorder associated gene
47:06mutations can be identified as in
47:09the small fraction of idiopathic
47:11hypereosinophilia or IHS cases,
47:13but they do appear to be present,
47:15and they may be sensitive in helping
47:18prove clonality in the study.
47:20Down by saw Wang at all,
47:22they found that in cases of
47:24Hypereosinophilic syndrome that
47:25were actually NGS positive,
47:27meaning they detected an abnormality.
47:30Those actually shared clinical and
47:32bone marrow finding overlap with
47:34chronic yeast anopheline leukemia Nos.
47:36So they really made the argument
47:38that if you find these genetic
47:39abnormalities and it's not chip,
47:41it's probably going to behave
47:43more like a CELNOS.
47:45So it can be useful to help it,
47:47you know, diagnose clonality
47:49in those particular situations.
47:50But again,
47:51remember you gotta exclude chip,
47:54and even though these studies are limited,
47:56I think this is pretty powerful in,
47:58you know information because it does
48:01indicate that NGSS is going to probably
48:03play a much more significant role
48:05in our diagnosis of these disorders.
48:09So next generation sequencing can be
48:12helpful in the border between IH E&amp;CEL,
48:15but what about morphology?
48:17So in another very interesting study,
48:19Doctor Sawang and and a bunch
48:21of her bone marrow
48:22pathology colleagues looked at
48:24exactly this question and what
48:26they found was bone marrow.
48:28Morphology matters,
48:28so if you have abnormalities
48:31such as Mark Hypercellularity,
48:34you have dysplastic features.
48:35You have increased blasts which would
48:37make sense or abnormal appearing.
48:39Gets in a field that really served
48:42to support a diagnosis more in
48:44keeping with a malignancy IE.
48:46Chronic eczema philic leukemia Nos
48:49rather than a reactive eosinophilic product.
48:52You know process so to me this
48:54provides support that in addition
48:56to our current WHO criteria it
48:59might be possible for us to include
49:02morphology in our diagnosis of CELNOS.
49:04OK, so let's return back to to my case.
49:08So I had actually ordered.
49:09Next generation sequencing.
49:10Because I was really that worried
49:12but it was cancelled by the
49:14clinical team because they thought
49:15the hypereosinophilia was due to
49:17the underlying pancreatic lesion.
49:18Plus we did not have any prior
49:21information or knowledge about CBC
49:23that would have shown that the
49:24that the hybrid is an affiliate
49:27predated this tubulovillous adenoma.
49:29But because of the persistent
49:30unexplained ES and affiliate,
49:32the patient had two subsequent bone marrows,
49:34one at 8 months and one at 14 months
49:36from the original presentation.
49:38They all looked identical.
49:39OK,
49:40so they had ESPN affiliate morphologically
49:42unremarkable hypercellular and scattered.
49:44You know,
49:45atypical or dysplastic clicking next.
49:47However,
49:48the third bone marrow,
49:49as you can see on the slide,
49:50showed a cytogenetic abnormality
49:52and basically 19 of 20 metaphyses.
49:55So this now enables us to confirm a
49:57diagnosis of chronic use in a physical
50:00tenia not otherwise specified.
50:02Similarly,
50:02at the 14 month bone marrow they also
50:05undertook next generation sequencing
50:07and we were able to identify.
50:102 genetic alterations,
50:121 in ASX 01 and the other an SRS of two,
50:15both of which are pretty common
50:16chip mutations.
50:17But the fact that there were two of
50:19them and not just one and the fact
50:21that the variant allele frequencies
50:22were in the high 40s really supports that.
50:25This was in fact a clonal process,
50:27so with this information,
50:29just as a research you know investigation,
50:31I actually went back to my original
50:33DNA extract and hold and we were
50:35able to document that those same
50:372 mutations at the same high V
50:39AF were actually present.
50:40The initial bone marrow biopsy
50:44So I think this case has several
50:47key messages as we sort of evolve
50:50our strategy in diagnosing
50:51hypereosinophilic conditions.
50:53First,
50:53morphology matters the
50:55marked hypercellularity,
50:57and those abnormal megas really were
50:59a clue that we were dealing to a
51:02primary clonal ESPN affiliate disorder.
51:04Second patients,
51:05they can have ticks and fleas, right?
51:08So this guy actually had two separate things.
51:10If there's so to me,
51:11if there's sufficient clinical
51:13or pathologic suspicion,
51:14we probably should be pushing those
51:17boundaries and really confirming whether
51:19a clonal process is or is not present.
51:21I think DNA,
51:22even RNA extracted and
51:23hold is not unreasonable.
51:25We don't see a ton of years
51:26in affiliate cases,
51:27so it's not like a huge burden on our system
51:29to process the specimens because you can
51:32always come back to it at a later date.
51:34You don't have to go and procure another
51:36bone marrow, but you can say OK,
51:37now we really need to do some RNA
51:40sequencing or you know XYZ type of testing.
51:43Third, I thought it was reasonable
51:44this patient was clinically stable.
51:46We knew he was having a whipple and they
51:48can always get him through that surgery.
51:50Get him recovered. And recheck the CDC,
51:52and if it's still persistent then we could
51:55have done the DNA evaluation at that point.
51:59So here's my final diagnosis.
52:00In this case, took us a while to get there,
52:02but I think it is the right one.
52:05So in summary, I hope I've convinced
52:07you that he is an affiliate,
52:09is not a straightforward disorder,
52:11and it can be quite complicated
52:13to work up in many instances.
52:15In fact, because Hypereosinophilia
52:17is relatively rarely encountered
52:20in routine clinical practice,
52:22and because it has a whole host of
52:25neoplastic and non neoplastic causes.
52:27I would advocate for a systematic
52:30yet comprehensive approach to the
52:32evaluation of these particular cases.
52:35Obviously your approach should be
52:36evidence based, and it should in all,
52:39in almost all likelihood continue to
52:41evolve as we gain additional knowledge,
52:44particularly from the genetic
52:45perspective about the molecular
52:47underpinnings of these disorders.
52:49Whenever possible,
52:50try and adhere and render diagnosis utilizing
52:53your most current classification system.
52:56Another important aspect that I emphasized
52:58earlier on is be astute at recognizing
53:01the heterogeneous heterogeneous
53:03ways these entities may present,
53:06including having a high index of suspicion.
53:09If you have a T lymphoblastic lymphoma in
53:12a lymph node or in the skin or something.
53:15Just be thinking about that if the
53:17S and affiliate is not present,
53:19and then in the words of Doctor Lebaron
53:21Washington he's a hematopathologist.
53:23He practices in Houston, he was a hematoma.
53:26Pathology fellow a couple of years
53:28ahead of me.
53:29I really appreciate this quote
53:31if it does not fit,
53:33you must not quit and this is so true
53:35and pathology it's true in clinical
53:37medicine and it's true in these
53:39sneaky cases of bias and affilia.
53:41So if your case doesn't make sense or
53:44something isn't adding up, don't give up.
53:47Continue your investigation.
53:49And with that,
53:49I thank you very much for your attention,
53:52and I'd be happy to take any questions.
53:58Thank you so much.
53:59I think that was the most clear
54:02presentation and walk through
54:04of esena Phillip disorders.
54:07Just want to see if anybody has questions.
54:09They want to just.
54:10Pop in or throw in the chat.
54:25OK Manji, you have an announcement.
54:28First of all I want to congratulate
54:31Doctor Richard for such a fantastic
54:34presentation on hypereosinophilic syndromes
54:38and this is so fitting because this is
54:41the last grand round of our academic year.
54:45So it's ending on a very high dot.
54:49If it does not fit, do not quit.
54:52I love that. Thank you.
54:56I actually have a question on you
54:58know we we have quite a few of these.
55:01Mastocytosis mast cell hyperplasia.
55:03Sometimes in the context of PDGFRA,
55:07PDGFRB rearranged tumors and,
55:11you know, without seeing how it rolls
55:15out genetically when you're trying
55:17to make that diagnosis at first,
55:18it can be very difficult.
55:21Whether you're going to actually
55:24call it SMTHN and.
55:26I wonder sometimes when you get
55:29everything back and you know.
55:31Of course you still mentioned
55:32that there is mastocytosis,
55:34but now it's PDGFRA or PDGFRB,
55:37really driving the whole process,
55:39especially without the KIT mutation,
55:42would you say that those patients
55:44really do not have a clinical
55:48behavior fitting with SM, or even
55:51yeah, so that is a great question.
55:53So this is me speaking, you know,
55:56just as me terminology is
55:58absolutely critical in a case.
56:00Those are not systemic mastocytosis cases.
56:03We have seen cases that present just
56:05the whole bone marrows we faced
56:07by spindled aggregated massels,
56:09but they have a PDGFRA not call those SM.
56:13Those are not SM.
56:14They do not need to be on my to
56:16store and they I mean they they they
56:18need to go a totally different way.
56:20So the way you know we had that SH
56:22EA HP Workshop a couple years ago
56:24and we actually talked about what?
56:27The terminology should be because The
56:28Who is not very helpful in this regard,
56:31and they actually say you know most
56:33cases of PDGFRA present as chronic
56:35chest and affiliate leukemia Nos.
56:37Please do not call it that either,
56:38because that's not what it is.
56:39That's a death sentence for the patient,
56:41right?
56:41So I think I would advocate the
56:44best way to sign these cases out.
56:46You saw the way I did the one
56:48with the 5th 1L1.
56:49I call it chronic myeloid
56:51neoplasm because it's not wrong.
56:52It has its own affilia and I
56:54specifically state with the genetic
56:56alteration is and I actually do.
56:57Not further subcategorize it because.
57:01In our current thinking of The Who you know,
57:04CML is its own thing.
57:06It has a triple hit genetics.
57:07It is not PDGFR beta rearranged so
57:10please do not call that CML with EOS
57:13and that PDGFR beta rearrangement.
57:15So I think you bring up a very very
57:17good point that while the terminology
57:19we have right now is kind of clunky,
57:21it it works because it conveys.
57:23Is it chronic or is it acute?
57:25You know which abnormality
57:27abnormality does it have,
57:29but you don't want to give the patient.
57:31For the clinician,
57:32the impression that it's going
57:34to behave like an SM,
57:35when in fact it has nothing
57:36to do with SM at all.
57:38So very very good point.
57:41And actually,
57:41if you see a case that you think is
57:44SM or has perivascular aggregates or
57:46peritubular and your kit is negative.
57:48And you've only activated the mass
57:49cell side of the pathway because
57:51you don't have ESPN affiliate,
57:52for example.
57:53Don't forget to do PDGFR alpha
57:55because you may prized.
57:59Yeah, one thing that I I'm sure
58:01you just didn't have time to get
58:03to is a lymphocytic variant of HHS
58:05which you know that work up for.
58:07US at least has been. Mainly, you know,
58:11instigated on the clinical side.
58:13I wonder how much have you guys just
58:17initiated the work up for LVHS versus,
58:20you know, getting the flow
58:21request and then doing the rest?
58:24Yeah, so we.
58:24I mean we to be honest with you.
58:26I mean I think maybe over 20
58:28years we've seen like 8 or 10.
58:29These cases that we actually think are LBHS.
58:32They're not like emerging
58:33PTCL or something like that,
58:35but because they exist and because
58:37you know the largest study was out of
58:40the NIH in terms of treatment since
58:42they respond so well to steroids,
58:44we actually do.
58:45Do we usually do peripheral blood
58:47flow for the aberrant T cell phones
58:49in every case of the US and affiliate
58:51just to get that out as a dot.
58:54Basically as a diagnosis so you
58:57know every now and then we get
58:58surprised when we get an abnormal.
59:00The cell clone,
59:01but almost all cases I would say
59:03upwards of 99% of the cases with
59:05ease and affiliate are negative
59:07by I think you know flow in most
59:10instances isn't that expensive,
59:12so I think you know again because
59:14it impacts the diagnosis,
59:16but it also impacts how this
59:18patient's going to be treated.
59:19I mean,
59:20it's just it's a totally different
59:21deal when it's LVHS versus it's a
59:24reactive Austin affiliate, right?
59:25Or a mass cell process the the will
59:28do something entirely different.
59:31Yeah, the flow for T cell panel is done,
59:33but I I think you know sometimes they're
59:36not thinking about that entity specifically
59:40and that's why we have it as part
59:41of our algorithm number one.
59:42I don't forget to do it,
59:44but I also you know it gets covered.
59:47Yeah. Yeah, no great question.
59:54All right, I think we're
59:55actually on the hour.
59:56If nobody has other questions,
59:59I just really want to thank
01:00:01Doctor Weikart for coming today
01:00:02and speaking to us and visiting.
01:00:04I hope that I'll be able to
01:00:06get you to physically come in
01:00:08and have some New Haven pizza.
01:00:11Yeah, that would be great.
01:00:12Yeah, thank you very much
01:00:13again for the opportunity.
01:00:14It was an absolute pleasure and
01:00:15I love meeting the people I did.
01:00:17And yeah, it was.
01:00:18It was a great day.
01:00:20Thank you so much.
01:00:22Mind you.