Studying Histopathology and CT Scans

[Sanzy]

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How much of a good idea is it to add histopathology (both micro and gross) slides from Pathoma into my notes this winter break? Should I have a really good grasp on the pictures, just a passing familiarity, or is it just a waste of time? I generally haven't heard how high-yield it is to know what small cell carcinoma or chronic cholecystitis looks like underneath the microscope.

Another question I have is about CT scans. I heard that it is pretty helpful to know these, and since it is something we haven't looked at since year one, I was wondering where I should start? Is it good enough to go through HY Neuroanatomy and Gross Anatomy and add those pictures into my notes? Anatomy has always been my weakest subject.

 

[cage92]

i have the same question how we can interpret ct scan without any clinical knowledge and what abou histopatho slides web path seem very condensed for the picturesss

 

[Kaputt]

90% of the time, you don't need the picture they give you to correctly answer the question. But the pictures are helpful, so know the ones in First Aid.

CTs are only used to demonstrate anatomy. You aren't expected to pick out pathology on CT scans. That's what a radiology residency is for.

 

[MrBeauregard]

I had to pick out pathology on a CT and an X-ray. So it's not just for radiology residents anymore.

 

[dragon529]

this is fun... the boards can throw all kinds of crazy **** @ you... just gotta prepare for the best.

 

[ijn]

You're approaching phloston territory of OCPDness if you're going to memorize what chronic cholecystitis looks like under a microscope. If you can't recognize what is high yield and what is low yield then you're going to have a hard time getting a good score. There is just so much out there that you could study. The key is recognizing what you don't need to know and allocating your time effectively on what is important (hint: NOT the histopathology of chronic cholecystitis or SCLC.)

 

[MrBeauregard]

If by SCLC you mean Small Cell Lung Carcinoma, I would definitely know what Kulchitsky cells look like.

 

[loveoforganic2]

^ I don't think that's even in big Robbins, unless I'm missing it

 

[thehundredthone]

If by SCLC you mean Small Cell Lung Carcinoma, I would definitely know what Kulchitsky cells look like.

It's an oat cell carcinoma, i.e. it's undifferentiated, light microscopy is not going to show you anything more than small blue cells.

 

[MrBeauregard]

^ I don't think that's even in big Robbins, unless I'm missing it

You're missing it. Chapter 15, under Tumors.

It's an oat cell carcinoma, i.e. it's undifferentiated, light microscopy is not going to show you anything more than small blue cells.

Small blue cells are the hallmark of the pathology. If you're missing that, you're missing it all.

From Robbins:

Small Cell Carcinoma. This highly malignant tumor has a distinctive cell type. The epithelial cells are relatively small, with scant cytoplasm, ill-defined cell borders, finely granular nuclear chromatin (salt and pepper pattern), and absent or inconspicuous nucleoli (see Fig. 15-43C ).

 

[ijn]

Distinctive? If I showed you a picture of any other small round blue cell tumor or perhaps a zoomed in lymphoma, then what is the difference? I assume pathologists have to do some sort of immunohistochemical stain to confirm the diagnosis. Most of those specific stains are beyond STEP 1, but maybe I'm wrong.

 

[loveoforganic2]

You're missing it. Chapter 15, under Tumors.



Small blue cells are the hallmark of the pathology. If you're missing that, you're missing it all.

From Robbins:

I meant specifically tying SCC of the lung to the term Kulchitsky cells, although to be fair, that isn't what you were saying earlier

 

[thehundredthone]

Small blue cells are the hallmark of the pathology. If you're missing that, you're missing it all.

You're telling me you can differentiate a small blue cell tumour of the lung from one in any other location just by light microscopy?

If the point you're making is that one should be able to distinguish a small cell carcinoma from a non small cell carcinoma, then yes, that is important. However Kulchitsky cells have absolutely no relevance in the histopathology, knowing what they look like will not help.

I assume pathologists have to do some sort of immunohistochemical stain to confirm the diagnosis. Most of those specific stains are beyond STEP 1, but maybe I'm wrong.

I thought chromogranin, synaptophysin and the third name which eludes me right now are within the realm of step 1?

 

[MrBeauregard]

I meant specifically tying SCC of the lung to the term Kulchitsky cells, although to be fair, that isn't what you were saying earlier

That is what I was saying:

From First Aid, p. 513:

Neoplasm of neuroendocrine Kulchitsky cells --> small dark blue cells (see Image 37).

You're telling me you can differentiate a small blue cell tumour of the lung from one in any other location just by light microscopy?

Of course not. But we aren't expected to do that. If given a stem describing a patient presenting with cough, hemoptysis, 50-pack-year smoking history, recent unintended weight loss, etc., and shown an image of small blue cells, you should pick SCLC.

If the point you're making is that one should be able to distinguish a small cell carcinoma from a non small cell carcinoma, then yes, that is important. However Kulchitsky cells have absolutely no relevance in the histopathology, knowing what they look like will not help.

Yes, my point was that one should be able to differentiate SCLC from NSCLC. And yes, Kulchitsky cells have much relevance. You may want to reference my statement above, or read the quotation from Robbins below.

From Robbins:

Electron microscopy shows dense-core neurosecretory granules, about 100 nm in diameter, in two thirds of cases. The granules are similar to those found in the neuroendocrine cells present along the bronchial epithelium, particularly in the fetus and neonate. Though distinctive, electron microscopy is not needed for diagnosis. The occurrence of neurosecretory granules, the ability of some of these tumors to secrete polypeptide hormones, and the presence of neuroendocrine markers such as chromogranin, synaptophysin, and CD57 (in 75% of cases) and parathormone-like and other hormonally active products suggest derivation of this tumor from neuroendocrine progenitor cells of the lining bronchial epithelium. This lung cancer type is most commonly associated with ectopic hormone production (discussed later).

 

[thehundredthone]

That is what I was saying:
Yes, my point was that one should be able to differentiate SCLC from NSCLC. And yes, Kulchitsky cells have much relevance. You may want to reference my statement above, or read the quotation from Robbins below.

From Robbins: Electron microscopy shows dense-core neurosecretory granules, about 100 nm in diameter, in two thirds of cases.

Keyword: Electron microscopy.

I can say with quite some confidence that it is highly unlikely that we will be expected to identify Kulchitsky cells on electron microscopy to clinch the diagnosis. Hence I reaffirm my statement: However Kulchitsky cells have absolutely no relevance in the histopathology, knowing what they look like will not help.

Yes, it's important to know that SCLC arises from Kulchitsky cells. Yes, it's important to know that they contain neurosecretory granules (perhaps even which ones). But it is not important to know what Kulchitsky cells look like on histopathology. Histopathology = light microscopy. In SCLC, all you will see, or rather need to see are small blue cells.

 

[MrBeauregard]

Yes, it's important to know that SCLC arises from Kulchitsky cells. Yes, it's important to know that they contain neurosecretory granules (perhaps even which ones). But it is not important to know what Kulchitsky cells look like on histopathology. Histopathology = light microscopy. In SCLC, all you will see, or rather need to see are small blue cells.

Do you not realize that Kulchitsky cell = small blue cell?

Key phrase: EM is not needed for diagnosis (per the Robbins quote). I'm not sure what you're arguing against.

http://missinglink.ucsf.edu/lm/ids_103_lung_cancer/subpages/histo.htm

http://en.wikipedia.org/wiki/Neuroendocrine_tumor under Histopathology.

 

[thehundredthone]

Do you not realize that Kulchitsky cell = small blue cell?

Making the other person out to be stupid doesn't make for good academic discussion. It's clear that you're holding off from straight out saying that you think I'm ******ed, but here's what I'm arguing against anyway:
http://en.wikipedia.org/wiki/Small-blue-round-cell_tumor
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2658025/
http://www.thedoctorsdoctor.com/diseases/small_round_blue_cell_tumor.htm

Not all small blue cells are Kulchitsky/neuroendocrine cells.

 

[MrBeauregard]

I'm absolutely not calling you ******ed.

And you are correct that not all small blue cell tumors are SCLC; however, in the context of the discussion (medical students taking Step 1 exam), if you know you are looking at lung (as suggested by the question stem) and see small blue cells, the Kulchitsky cells in this case, that is SCLC, and that association should not be missed. My statement that a Kulchistky cell = small blue cell is true, but I never said that small blue cells are only Kulchitsky cells. After looking at your links, two of them spoke of SRBCTs that commonly occur in children. SCLC isn't likely to occur in children due to it having a rather strong association with cigarette smoking in direct proportion to pack-year.

We aren't going to be given a histopathology slide showing small blue cells, without any stem, and be asked to identify the tumor. If that were the case, you are definitely correct that all we would see are "small blue cells" and it would be nearly impossible to make a diagnosis. We will be given an image, in context, with a stem. So again, in the context of lung pathology, if we see the term Kulchitsky cell, see small blue cells on an image, see the term small cell carcinoma, in any combination, we should equate them with one another. That's pretty much all I'm saying.

Again, I'm definitely not calling you ******ed.

 

[thehundredthone]

I'm absolutely not calling you ******ed.

Don't mind me, I'm 2 weeks out and a little high strung, that's all.

And you are correct that not all small blue cell tumors are SCLC; however, in the context of the discussion (medical students taking Step 1 exam), if you know you are looking at lung (as suggested by the question stem) and see small blue cells, the Kulchitsky cells in this case, that is SCLC, and that association should not be missed.

Agreed.

My statement that a Kulchistky cell = small blue cell is true, but I never said that small blue cells are only Kulchitsky cells.

Which was basically what I was trying to say, and we ended up going in circles. Anyway, point taken. I think though, that we all come in with preconceived notions about what's important, and either my n=1 experience will validate them or it won't.

Again, I'm definitely not calling you ******ed.

I think I was quite passive aggressive there, apologies. I'm not used to generally serious internet forums haha.

 

[MrBeauregard]

Well, I'm glad we got that behind us.

I honestly just want to try to help people out here. I read so many freaking posts on this forum before I took Step 1 and so many of them were very helpful, I just want to sort of keep it going. The last thing I want to do is call someone ******ed (and there are some pretty smart cats on this forum).

Anyways, it's probably a huge toss-up to study histopathology slides. I think I had about 7-10 between USMLE and COMLEX (and that's 722 questions), so the odds aren't too high. I guess, like ijn said, it's all about picking out the highest-yield; if you think it's good for you, do it. If you think it's not, don't.

I did have to stage CIN on my exam, and lucky for me I studied that. I also had two uterine histopathology slides (one on USMLE and one on COMLEX), both of which I still have absolutely no clue as to what they were trying to get me to answer. There were no clues that I could pick out in the stem. It's almost as if they wanted me to diagnose based purely on the slide.

 

[ijn]

I thought chromogranin, synaptophysin and the third name which eludes me right now are within the realm of step 1?

Those would stain any neuroendocrine cell though, no? You couldn't use it to differentiate carcinoid vs paraganglioma vs neuroblastoma, etc. I looked up the immunohistochemistry staining for SCLC and the source I read states that the main ones used for the ddx are CD56, TTF-1, MNF116. Personally I had only heard of TTF-1 before during basic science lectures on lung pathology, but even at that point I blew it off as the lecturing pathologist teaching a bit beyond what second years need because none of those stains are mentioned in Kaplan, First Aid, BRS, or Pathoma.

 

[Kaputt]

I had to pick out pathology on a CT and an X-ray. So it's not just for radiology residents anymore.

You are likely exaggerating. Only extremely classic pathology that is fair for a 2nd year med student would be admissible as a question requiring imaging on Step 1 (like a pneumothorax, widened mediastinum, etc). You guys act like every facet about medicine is fair game on this exam. It's not. This is Step 1.

 

[MrBeauregard]

You are likely exaggerating. Only extremely classic pathology that is fair for a 2nd year med student would be admissible as a question requiring imaging on Step 1 (like a pneumothorax, widened mediastinum, etc). You guys act like every facet about medicine is fair game on this exam. It's not. This is Step 1.

I'm definitely not exaggerating.

I'm being honest and telling future takers what I had to do. I didn't say it wasn't something easy, but I had to do it. It was also pathology that I had never seen an image of before.

Take it for what you will!

 

[ijn]

I've seen some pretty ******* CT questions before on CBSEs. One made you look at a horizontal CT abdominal and asked you to identify the labeled region. You had to pick between duodenum, jejunum, ileum and pancreas based on tiny as hell, poor resolution image. Thankfully my actual STEP 1 didn't have anything that ridiculous. I'll never understand why the NBME insists on using such poor quality images. It's 2012, for christ's sake.

 

[Kaputt]

I've seen some pretty ******* CT questions before on CBSEs. One made you look at a horizontal CT abdominal and asked you to identify the labeled region. You had to pick between duodenum, jejunum, ileum and pancreas based on tiny as hell, poor resolution image. Thankfully my actual STEP 1 didn't have anything that ridiculous. I'll never understand why the NBME insists on using such poor quality images. It's 2012, for christ's sake.

But that's anatomy, not pathology. I had some awful anatomy questions on my actual exam (that weren't imaging related).

 

[thehundredthone]

Those would stain any neuroendocrine cell though, no? You couldn't use it to differentiate carcinoid vs paraganglioma vs neuroblastoma, etc.

If they're going to ask me to differentiate 2 neuroendocrine tumours based purely on histopath/EM I'm going to pick any reasonable answer, move on and never look at the question again.

But, if the question was about a lung tumour and they asked what special stain could possibly be used for the given small cell tumour, then knowing chromogranin and synaptophysin would be useful.