Waaaah.

[stickydick]

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So I just started residency, and for the most part, I really like it. Started out on surg path which has roughly 12-14 hours at my spot, which is do-able...except that there is not really time to read (except at the weekends which are (currently) free.)

This is kind of a silly thing to say so early, but damn, I am finding microscopy hard. I can always contribute, but have no idea where to start with the unknown conference type deals...either simulated or real (ie patient with mystery lung nodule on a frozen day.) Where do you start? What framework do you use to find out something that is truly unknown?

By the way, any good books related to something like this? What about the 'differential diagnosis' book by Haber?

Thanks,

SD

 

[mlw03]

i just did a month of path as an MS4 and i think a lot of it comes down to recognizing patterns, and that can only come through experience. i mean, a lot of the diagnoses the attendings eventually signed out were things i'd never heard of. and they weren't things in robbins, so i couldn't really read up on them, but i was told that the big surg path texts do have them. so if your program does system based signout, i'd suggest reading those sections in your text to start familiarizing yourself with stuff. if general signout, start with the big systems that you see a lot of at most places: GI, prostate, lung, skin, etc.

once i started recognizing things a bit my approach for a specimen would be to first try and identify the tissue, then decide normal or abnormal. if abnormal, how so? i tried to start at the epithelial surface and then work deeper. are there too many inflammatory cells? is there granulation tissue? granulomas? any organisms visible? abnormal glands, and if so, how are they abnormal? when i did signout sometimes the attendings would literally say to me, "what do you see?" and i'd start to describe what i saw, and in doing that it would help me make a diagnosis.

i learned that path is like any other field in that there are diagnostic criteria for everything, and it just takes time to learn those criteria the same way we had to learn clinical diagnostic criteria as MS3s. just keep plugging away SD and you'll slowly begin to learn it, like the thousands before you and, hopefully, like me to follow.

 

[deschutes]

The general algorithm for evaluating an unknown slide (with notes related to conference participation) is:

Low-power:

(1) Say what the type of specimen is: "biopsy" (for derm, also state "shave" or "punch") vs. surgical resection

(2) Identify any residual normal histology - helps identify site, if not already provided.
- also look at the junction and interaction of the pathologic process with normal tissue: is it "infiltrative"? "well-circumscribed" with pseudo/capsule, i.e. compressing surrounding normal-appearing tissue vs. fibrotic wall

Medium-to-high power:

(3) Cellularity: High or low?

(4) Inflammation: present or absent? Granulomas - caseating (hopefully not!) vs. non-caseating? Remember that granulomas are defined by epithelioid histiocytes, not by giant cells.

(5) Cell features: large vs. small size? shape: round, ovoid, elongated? well or ill-defined cytoplasmic borders, syncytial? chromatin: dark and clumped vs. fine and open

(6) Any features of malignancy: Increased nuclear:cytoplasmic ratios, mitotic figures (abnormal or frequent), necrosis, prominent nucleoli, infiltrative borders?

(7) Possible type of neoplasm:

Epithelial neoplasm?
...cohesive cells
...Forming papillary structures/glands/mucus/signet-ring cells (AdenoCa)?
...Keratin pearls (SquamCa)?

Spindle cell neoplasm?
...long, thin tapered cells
...bone/cartilage/blood vessel/muscle/nerve tissue formation?

Lymphoma?
...smaller cells compared to carcinoma: use a neighbouring lymphocyte/RBC/endothelial cell as yardstick
...single cells infiltrate surrounding tissues

Neuroendocrine?
...so-called "salt and pepper" chromatin

(8) Any special stains or other ancillary testing you would do

(9) If all else fails, make a conclusion: "Reactive" or "Neoplastic"? If neoplastic, do you favour "benign" or "malignant"? "Primary" vs. "metastatic"?

 

[TheCritic]

The general algorithm for evaluating an unknown slide (with notes related to conference participation) is:

Low-power:

(1) Say what the type of specimen is: "biopsy" (for derm, also state "shave" or "punch") vs. surgical resection

(2) Identify any residual normal histology - helps identify site, if not already provided.
- also look at the junction and interaction of the pathologic process with normal tissue: is it "infiltrative"? "well-circumscribed" with pseudo/capsule, i.e. compressing surrounding normal-appearing tissue vs. fibrotic wall

Medium-to-high power:

(3) Cellularity: High or low?

(4) Inflammation: present or absent? Granulomas - caseating (hopefully not!) vs. non-caseating? Remember that granulomas are defined by epithelioid histiocytes, not by giant cells.

(5) Cell features: large vs. small size? shape: round, ovoid, elongated? well or ill-defined cytoplasmic borders, syncytial? chromatin: dark and clumped vs. fine and open

(6) Any features of malignancy: Increased nuclear:cytoplasmic ratios, mitotic figures (abnormal or frequent), necrosis, prominent nucleoli, infiltrative borders?

(7) Possible type of neoplasm:

Epithelial neoplasm?
...cohesive cells
...Forming papillary structures/glands/mucus (AdenoCa)?
...Keratin pearls (SquamCa)?

Spindle cell neoplasm?
...long, thin tapered cells
...bone/cartilage/blood vessel/muscle formation?

Lymphoma?
...smaller cells compared to carcinoma: use a neighbouring lymphocyte/RBC/endothelial cell as yardstick
...single cells infiltrate surrounding tissues

Neuroendocrine?
...so-called "salt and pepper" chromatin

(8) Any special stains or other ancillary testing you would do

(9) If all else fails, make a conclusion: "Reactive" or "Neoplastic"? If neoplastic, do you favour "benign" or "malignant"? "Primary" vs. "metastatic"?

Very good post!!! I hope other residents will add to this if possible. Yaah, others??? Anything to add for MS4s and 1st year residents starting out with unknowns.

 

[stickydick]

Yeah, that is awesome...appreciate it, sincerely. Anything else would indeed be appreciated!

 

[DarksideAllstar]

I think Deschutes' post is a great way to approach things. Its good to have an algorithm to follow, and after awhile you'll be able to go through it without even thinking about it. My only advice is not to get hung up on the subtleties your first couple of months on surgicals-- it can be very frustrating if you dont keep things in perspective. The more you see things, your eyes will be drawn to the things that "stick out" at you. Gradually, you'll get away from having to look at everything under 10x/20x/40x and start scanning at 2x/4x and will be surprised at how much you can see.

 

[yaah]

Very good post!!! I hope other residents will add to this if possible. Yaah, others??? Anything to add for MS4s and 1st year residents starting out with unknowns.

First principles, Clarice. Simplicity. Read Marcus Aurelius. Of each particular thing ask: what is it in itself? What is its nature?

You have to develop your own style. But you have to distill things down to simplicity. As deschutes said, ask what it is, why was it done, what is abnormal about it (and why), what are the relationships of abnormal to normal. Of course, you also have to ask yourself if you recognize what is abnormal and what is normal, often the toughest part. And that largely comes from experience.

As for how to do your work and still find time to read, well, try to read about things that confuse you or that you got wrong, learn as you go. Don't read the entire chapter every time you get a specimen of a certain organ. Review parts of it. It will start to make more sense as you go and things will start to click. And you will start to think about it less and less. Don't expect to be an expert diagnostician right away.

 

[deschutes]

I added signet ring cells under "AdCa" and nerve tissue under "spindle cell neoplasm".

Don't read the entire chapter every time you get a specimen of a certain organ. Review parts of it.

I can safely say it took me years to figure this out... *facepalm*

 

[pathgrrl]

Thanks Deschutes, this is a great description. I just finished my path elective and that would have been a great guideline to go into it with.