Top 10 learning issues for hemepath

[E.A. Poe]

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Any opinion on what the top 10 (Or so...) bread and butter, must know issues are for hemepath? Starting my rotation tomorrow gonna study up!

 

[deleted314957]

#1 Hematologic Disorders by Kjeldsberg, et.al. ASCP press
#2 Neoplastic Hematopathology by Knowles
#3 Wintrobe's Clinical Hematology

I'll think of the other 7 later

 

[2121115]

Memorize the WHO Book... down to the page numbers.

 

[pathstudent]

1. The differential for low grade B-cell lymphomas and their classic immunophenotypes

2. The distinction between Nodular LP Hodgkin and Classic Hodgkin

3. Everything about CML

4. The basics about the other myeloproliferatives

5. Get familiar with AML (Recurrent genetic aberrations, therapy related, MDS related, NOS)

6. Get familiar with MDS (clinical, histologic and cytogenetics)

7. Anemias (microcytic, marcorcytic, normocytic)

8. Burkitt vs DLBCL

9. The very basics of flow

10. The very basics of ancillary tests (FISH probes for MYC, BCL-2 etc..., FISH for MDS, FISH for BCR-ABL, PCR for Jak-2, BCR-ABL, FLT-3 etc...)

 

[Parts Unknown]

1. The differential for low grade B-cell lymphomas and their classic immunophenotypes

2. The distinction between Nodular LP Hodgkin and Classic Hodgkin

3. Everything about CML

4. The basics about the other myeloproliferatives

5. Get familiar with AML (Recurrent genetic aberrations, therapy related, MDS related, NOS)

6. Get familiar with MDS (clinical, histologic and cytogenetics)

7. Anemias (microcytic, marcorcytic, normocytic)

8. Burkitt vs DLBCL

9. The very basics of flow

10. The very basics of ancillary tests (FISH probes for MYC, BCL-2 etc..., FISH for MDS, FISH for BCR-ABL, PCR for Jak-2, BCR-ABL, FLT-3 etc...)

11. Understand the M:E ratio.

 

[pathstudent]

11. Understand the M:E ratio.

don't waste your time with m:e ratio. it's stupid, poorly defined, and not used to classify any disease processes that I ever learned, except sort of maybe for erythroleukemia. if there is an obvious erythoid or myeloid weighted population, it is obvious in the qualitative sense. in fact, doing differential counts at all is pointless in most cases. Counting blasts vs non-blasts takes care of most cases where a differential would be useful.

#11 should be plasma cell dyscrasias.

 

[KCShaw]

I just remember how confusing it was when my attending started rattling off obscure and difficult to interpret very complex lists of immunostains. Early on, try to focus on the big picture, common appearances THEN common stains to separate just the big categories. Reviewing the normal acquisition of certain markers during normal maturation helped put it together for me, rather than trying to memorize markers for each individual malignancy from scratch. Honestly, I found some of the condensed study materials such as from Osler, ASCP, or Sinard more useful in gaining that big-picture appreciation during early study. The reference texts are just that -- references. Great for after you get a grasp of the basics, but potentially confusing before that. But I agree that the WHO book, at least a few short years ago, seemed to be the best thing out there for tumor related info.

I thought Kjeldsberg was only OK, just not a lot of good alternatives for that kind of intro-ish text.

I agree understanding plasma cell problems is probably worth learning early; clinicians always seem to be asking about those.

 

[malchik]

1. The differential for low grade B-cell lymphomas and their classic immunophenotypes

2. The distinction between Nodular LP Hodgkin and Classic Hodgkin

3. Everything about CML

4. The basics about the other myeloproliferatives

5. Get familiar with AML (Recurrent genetic aberrations, therapy related, MDS related, NOS)

6. Get familiar with MDS (clinical, histologic and cytogenetics)

7. Anemias (microcytic, marcorcytic, normocytic)

8. Burkitt vs DLBCL

9. The very basics of flow

10. The very basics of ancillary tests (FISH probes for MYC, BCL-2 etc..., FISH for MDS, FISH for BCR-ABL, PCR for Jak-2, BCR-ABL, FLT-3 etc...)

Best pathstudent post ever

 

[Parts Unknown]

don't waste your time with m:e ratio. it's stupid, poorly defined, and not used to classify any disease processes that I ever learned, except sort of maybe for erythroleukemia. if there is an obvious erythoid or myeloid weighted population, it is obvious in the qualitative sense. in fact, doing differential counts at all is pointless in most cases. Counting blasts vs non-blasts takes care of most cases where a differential would be useful.

#11 should be plasma cell dyscrasias.

I was just recalling this classic.

 

[pathstudent]

I was just recalling this classic.

I was just pointing out that according to stedmans erythroids and megs are also myeloids.

Words need to mean something, no? Or should we just make **** up as we go along

That's ok you worry about defending the m:e ratio. I would stick with knowing the eleven things I listed above and question convention when you see that convention could be bull****.

 

[ScotchBonnet]

I am a stickler for correct/precise usage of vocabulary and have always thought the term "myeloid" is confusing as well. It does seem that most people use myeloid and granulocyte interchangeably. When you look at those charts that show the stages of development from the pluripotent stem cell to all of the mature types of blood cells, the first division is into myeloid and lymphocytic. It is from the myeloid stem cell that not only PMNs but also RBCs and platelets arise. Plus, as has been pointed out, the WHO classifies PV, ET, etc. as myeloid disorders. I don't know for sure who is correct, but I am leaning with pathstudent on this one.

 

[pathstudent]

I am a stickler for correct/precise usage of vocabulary and have always thought the term "myeloid" is confusing as well. It does seem that most people use myeloid and granulocyte interchangeably. When you look at those charts that show the stages of development from the pluripotent stem cell to all of the mature types of blood cells, the first division is into myeloid and lymphocytic. It is from the myeloid stem cell that not only PMNs but also RBCs and platelets arise. Plus, as has been pointed out, the WHO classifies PV, ET, etc. as myeloid disorders. I don't know for sure who is correct, but I am leaning with pathstudent on this one.

Yes erythroids aren't myeloids but a proliferation of megakaryoblasts and erythroblasts are acute myeloid leukemias. Et pmf and pv are myeloid neoplasms.

Another funny thing is I have seen some people not include eos or basos in the m:e rATio. WTF

the me ratio is stupid and should be questioned

 

[Parts Unknown]

I was just pointing out that according to stedmans erythroids and megs are also myeloids.

They are myeloid in that their site of origin within the body is the marrow. However, in practice the term reserved for white blood cells (other than lymphocytes). Erythroids and erythroid precursors are obviously not white blood cells, so a distinction is generally appreciated between these lineages.

Using your logic, I could perhaps make the case that the lower uterine segment and the human neck are synonymous anatomic structures as they are both cervical.

Words need to mean something, no? Or should we just make **** up as we go along

We should apply convention until there is a sound reason to alter our practice. You have not provided one.

 

[Parts Unknown]

Plus, as has been pointed out, the WHO classifies PV, ET, etc. as myeloid disorders.

The WHO classifies them as myeloproliferative disorders, not myeloid disorders. In this context the term is being used in the sense of an overall proliferation of marrow (myeloid) elements, not a proliferation of a specific subset of marrow cells. And indeed, one of the key histologic findings in both of these diseases is panmyelosis, or a proliferation of all the precursor lineages within the marrow compartment.

You can see the same terminology phenomenon in myelodysplastic syndromes, which can show aberrant morphology in any or all of the lineages (not just the granulocytic cells).

In summary, the term myeloid is used in two ways:
1. In reference to anything originating in the marrow (myeloproliferative, myelodysplastic, etc)
2. In reference to all non-lymphocytic white cells (when doing a diff, etc.)

Pathstudent's basic error is that he conflates the two uses. If you keep this in mind it will clear up some of the confusion.

 

[KCShaw]

Language being what it is, there will almost certainly always be points of confusion. It would be quite nice if, especially when learning or teaching something, one could say that X means one thing and Y means another -- rather than X means one thing sometimes and another thing other times, it all depends, but don't worry you'll figure it out. Except sometimes when we use certain words to pretty much always mean a certain thing.

I remember in my first few days of residency having a tendency to use the word "atypical" to describe a cell or tissue that just...didn't look normal to me. I didn't mean to imply something approaching dysplasia, but because I didn't know what I was looking at I didn't have a more descriptive explanation. My bosses didn't like that, although in broad terms it was probably accurate usage. The more I and my peers learned to describe and use terms that had consistent and more concise meanings within the realm of pathology, the easier life became. Unfortunately the magic of medicine includes the persistent conventions and consistent inconsistencies. Unnecessary though they may be, for the most part their intents are well understood by Those In The Know, often well described in the literature, and generally neither "need" to be changed nor is there a significant motivation to do so solely to be more clear to Those Not In The Know.

As one of my science teachers put it many years ago, we use funny words in funny ways so people WON'T understand what we're talking about, and we'll look smarter. It was his way of simplifying science while bringing the class together into a little funny-talking club. At the time I thought he was mainly being a dork, but there's a certain truth to it.

 

[pathstudent]

The WHO classifies them as myeloproliferative disorders, not myeloid disorders. In this context the term is being used in the sense of an overall proliferation of marrow (myeloid) elements, not a proliferation of a specific subset of marrow cells. And indeed, one of the key histologic findings in both of these diseases is panmyelosis, or a proliferation of all the precursor lineages within the marrow compartment.

You can see the same terminology phenomenon in myelodysplastic syndromes, which can show aberrant morphology in any or all of the lineages (not just the granulocytic cells).

In summary, the term myeloid is used in two ways:
1. In reference to anything originating in the marrow (myeloproliferative, myelodysplastic, etc)
2. In reference to all non-lymphocytic white cells (when doing a diff, etc.)

Pathstudent's basic error is that he conflates the two uses. If you keep this in mind it will clear up some of the confusion.

Give it up dude and quit talking out your ass. Your summary is totally off.

According to your number 1 - B-lymphoblastic leukemias that originate in the marrow should be myeloid leukemias. A primary lymphoma in the marrow would be myeloproliferative.

and

things like proliferations of megakaryoblasts and erythroid precursurs are classified as myeloid leukemias and by your number 2 they should not as they are not myeloids.

So no matter what you are wrong.


I think everyone knows the difference and understands what is meant by myeloid in the proper context but whoever started the convention of defining myeloids as neutrophils and precursors was screwed up as the word myeloid already was defined as something that contained neutrophils and precursors as a subset. It is bad logic. And if you are intelligent, you can understand that it is bad logic and poorly defined.

 

[lipomas]

Actually, the word "myeloid" refers to origin in the bone marrow. It's a word of Greek origin. So you are just arguing semantics. Of course the term "myeloid cell" does not include lymphoid cells and their precursorsn in common parlance, but you could argue semantically based on the origins of the word myeloid that a lymphoid neoplasm arising in the bone marrow is a myeloid neoplasm. But that is not the point.

How else would you explain that a "myeloma" is not a myeloid cell tumor either, but a neoplasm that replaces bone marrow (myelo-oma). If you define the word literally a myeloma should be a tumor composed of bone marrow. But we don't call them that. We call that extramedullary hematopoiesis, although we call adrenal tumors with fat + bone marrow myelolipomas. If it has no fat, should it be called a myeloma? We could parse your words further and say that only granulocytic sarcomas should be called myelomas, because they are solid neoplasms of myeloid cells.

Personally, I do not get hung up on the M:E ratio because I find it meaningless and arbitrary. I just report the actual differential. Reporting M:E ratios has always struck me as a lazy way to avoid actually doing full differential counts.

 

[2121115]

Let's be honest here. Pathology is full of misnomers. The term "myeloid" is far from the only one.

 

[pathstudent]

The WHO classifies them as myeloproliferative disorders, not myeloid disorders.

Dude, you so don't know what the hell you are talking about.

CML, PV, PMF, ET etc ... absolutely are myeloid neoplasms. Check out this paper by Vardiman. http://www.ncbi.nlm.nih.gov/pubmed/12239137

Listen people, listen to Vardiman and pathstudent over parts unknown who just talks out his ass for the sake of arguing and doesn't have a clue.

Saying granulocyte= myeloid cell is a totally abomination of logic and etymology.

Saying the M:E ratio equals granulocytes neutrophils divided by erythroid precursors denies the definition of myeloid.

 

[Parts Unknown]

Give it up dude and quit talking out your ass. Your summary is totally off.

No no, you can look it up. Lipomas is correct, the term "myeloid" comes from the Greek root "myelos-" which simply means "pertaining to the bone marrow" (it also means "pertaining to the spinal cord," but we won't go there). So it is absolutely sensible to classify AML, CML, ET, PV, etc. as myeloid processes. I think we can agree on this. I also think you absolutely could make a case for calling a lymphoid tumor unequivocally arising from the bone marrow as a myeloid neoplasm. Find a case and write a letter to Blood.

As an aside, in terms of erythroid leukemia I would note that by far most common subtype requires >20% myeloblasts among the non-erythroid cells. But that is neither here nor there.

Interestingly, 100+ years ago this prefix was applied to tumors of both hematopoietic and non-hematopoietic origin. Many orthopedic neoplasms were called myelogenic sarcomas, as they were presumed to arise from marrow components rather than bone or joint elements. As knowledge expanded they were eventually reclassified.

The other use of myeloid that drives you so crazy is simply a bit of vestigial language reflecting the evolution of the terminology. You can still spot it here and there, like old fingerprints.

Myeloblast
Promyelocyte
Myelocyte
Metamyelocyte
Myelomonocytic leukemia (odd considering that monocytic are grouped with granulocytic cells in the M:E ratio, at least that's how I learned it)
Myeloid sarcoma (formerly termed granulocytic sarcoma, at times)

It is bad logic.

You would be hard pressed to see language as a logical endeavor. It is ambiguous, arbitrary, redundant, convention-driven, full of exceptions, and constantly evolving. Why not dig your panties out of your butt and enjoy it?

 

[zao275]

Back to OP's question: I agree that Adam Bagg's Osler lectures on Hemepath were fantastic (not to mention funny and entertaining). I found them VERY useful when studying for both CP AND AP boards. Just FYI.