View source for Emergency pathology

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|author1=[[User:Mikael Häggström|Mikael Häggström]]
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<noinclude>This article deals with the more time-sensitive matters encountered within pathology, and is written mainly for new pathology trainees.

</noinclude>{{Memorization-worthy}} Information relating to emergent pathology is often not conveniently and timely looked up when needed because of the urgency in reaching a report. 

{{Comprehensiveness}}
==Frozen sections==
Even new pathology trainees may end up being the first responders to frozen sections (as well as intraoperative consultations by gross inspection only). 

===Preparation===
Prepare at least the following:
*Finding out '''which senior to call for help''' if responding to a frozen section. A fairly new pathology trainee should generally not independently make a report to the referring physician without having at least consulted with a senior, and therefore the diagnostics of frozen section slides is not included in this section. In the meantime, ensure that you have the contact information to relevant seniors and/or attendings, and the means to perform '''[[micrography and telepathology]]''' if that person may not be able to be physically present within an acceptable time. Also consider calling additional colleagues, even at your own level or below, if there are many specimens coming at once.
[[File:Metastasis sites for common cancers.svg|thumb|270px|Main sites of '''metastases''' for some common cancer types. Primary cancers are denoted by "''...cancer''" and their main metastasis sites are denoted by "''...metastases''".<ref>A list of included entries and references is found on main image page in Wikimedia Commons: [https://commons.wikimedia.org/wiki/File:Metastasis_sites_for_common_cancers.svg#Summary Commons:File:Metastasis sites for common cancers.svg#Summary]</ref>]]
*If possible, look up pertinent '''medical histories''' of potential cases that may appear as frozen sections or other forms of intraoperative consultations. For example, surgery departments may have schedules of patients for the day that you will cover frozen sections. On such lists, types of surgeries that often come as intraoperative consultations mainly include potentially malignant skin excisions, lung excisions (larger than biopsies), ovarian tumors, and samples from other common metastasis sites (lungs, liver, brain, bone). The most important details to find out are:
:*'''What you may do''' yourself if you will be alone when you get the specimen, or if you need to wait for particular seniors before doing potentially irreversible steps such as [[inking]] and sectioning.
:*'''Previous biopsies'''. For expected excisions from common metastasis sites, look thoroughly for any past cancer diagnoses. Note the pathologic diagnoses of the biopsies{{Comprehensive-begin}}, as well as the collection dates and accession numbers.{{Comprehensive-end}} {{Moderate-begin}}Pull out previous slides of the malignancy so that you can compare its appearance with the current case.{{Moderate-end}}
:*'''Tumor sizes''' where applicable{{Moderate-begin}}, and whether the estimation was from imaging or microscopy{{Moderate-end}}.
*Make sure you have a working '''microtome'''. Switch its blade if you are not certain it has had limited use.
*Prepare at least as many '''chucks''' as you think you will need according to any surgery schedule (or at least 3 of preferably various sizes).
<gallery mode=packed heights=140px>
File:Frozen sectioning 1 putting embedding medium on chuck.jpg|You can theoretically put a specimen directly on the chuck plate, but to reduce the risk of tearing, put embedding medium on empty chucks
File:Frozen sectioning 2 waiting until bottom is frozen.jpg|Wait until the embedding medium is frozen at the bottom
File:Frozen sectioning 4 putting conductor on chuck.jpg|Place the conductor on top of the chuck. You now have a prepared chuck with a smooth surface.
File:Frozen sectioning 3 putting cryostat oil on conductor.jpg|Smear some oil on the bottom of the conductor, to avoid it getting stuck to the specimen later.<ref group=note>Do not smear oil on the bottom of the conductor before placing it on a chuck without a specimen, for chuck preparation, as it may (theoretically) cause breakage of the specimen later because of slippage of a segment over the oil layer.</ref>
</gallery>
{{Moderate-begin}}If you don't have a conductor, or if the embedding medium completely hardened before you applied it, perform cryotomy of the embedding medium to get a larger and smoother top.{{Moderate-end}}

*Inspect the '''H&E staining''' containers and refill if necessary.
<gallery mode=packed heights=250px>
File:Setup for HE staining of frozen section slides.jpg|Example of material needed for H&E staining of frozen sections: Staining fluids, glass slides, pencil to mark slides (the ink of pens will generally be washed off in the fluids), slide dipper, timer, cover slips and immersion oil.
</gallery>
*Ensure that you have '''frozen section medium''', as well as '''cover slips''' and '''mounting fluid'''.

===Performing frozen sectioning===
*'''Inform''' relevant seniors.
*Look at any '''requisition form''' or otherwise check or confirm what answers the requesting clinician wants. When the histopathologic type of tumor is known from before and its distance to the closest margin is relatively far, a gross intraoperative consultation is generally enough to measure that distance.
*'''Measure''' the size of the specimen.
*If you are permitted to proceed with the following steps, which are potentially irreversible, still consider whether there are any '''surprising aspects''' that requires you to wait until a senior arrives.
*'''[[Ink]]''' relevant margins
*'''Section'' the specimen so as to be able to see relevant pathologies, and closest distances to relevant margins.
*'''Select''' tissue to be able to answer the clinician's questions. 
*'''Trim''' samples to make them equally thick, since you will need to section away more from thick pieces before thinner pieces will appear in cryotomy slices.
<gallery mode=packed heights=170px>
File:Frozen sectioning 5 putting specimens on chuck.jpg|Put specimens on one or more chucks. It's better to put them on a slightly too large chuck than a slightly too small one, but keep the areas of interest within what presumably fits on a microscopy slide.
File:Frozen sectioning 6 Covering with embedding medium.jpg|Cover the specimen with embedding medium
File:Frozen sectioning 7 apply conductor.jpg|Apply a conductor (unless it's a thin specimen that needs to stand on its side)
File:Frozen sectioning 8 using freeze spray.jpg|Use freeze spray to quicken the freezing if available
File:Frozen sectioning 9 Breaking off embedding medium that reach below the chuck's plate.jpg|Breaking off any embedding medium that reaches below the chuck's plate
File:Frozen sectioning 10 Fastening the chuck on the cryotome and cutting relatively thick sections until the full tissue surfaces of interest are exposed.jpg|Fasten the chuck on the cryotome. Epithelial surfaces should be oriented vertically, like a picket fence.
File:Frozen sectioning 11 Setting the thickness to for example 5 micrometer and sectioning while holding the section down to prevent it from folding onto itself.jpg|Generally set the thickness to 5μm, and advance the specimen over the blade while holding the section down to prevent it from folding onto itself 
File:Frozen sectioning 12 Continuing until all the tissue of interest is in the section.jpg|Continue until all the tissue of interest is in the section. Leave at least a small part connected to the chuck to avoid folding.
File:Frozen sectioning 13 Putting a glass slide on the tissue - version 2.jpg|Put a glass slide on the tissue (this case is actually borderline too spread out to fit on one slide). It is now ready to be put in staining solutions:
</gallery>
[[File:Time in solutions for frozen sections.jpg|thumb|350px|center|Minimal time in solutions for frozen sections.]]
{{Question|title=Hematoxylin in frozen sectioning}}
You are put on frozen sectioning duty, and a specimen arrives. You inform the attending over the phone, who will require a moment to reach the room, and therefore tells you to prepare two microscopy slides in the meantime. You make sections, but the note that instructs the number of dips or duration in the hematoxylin solution has become unreadable due to a hematoxylin stain. You don't have any phone signal in the frozen section room, so you don't have time to look it up. To what extent will you put the slide in the hematoxylin solution?
*A. 1 minute and 30 seconds
*B. 1 dip
*C. 10 seconds
*D. 5 dips
;Answer
[[File:Time in hematoxylin solution.jpg|200px]]

;Explanation
This is generally the minimal time required for proper hematoxylin staining during frozen sections. Yet, if you know the solution is not expired or diluted, and you are really in a rush, then you can possibly have it acceptably stained in 1 minute in hematoxylin.
{{Question-end}}

===Troubleshooting===
{|class=wikitable
! Problem !! Cause !! Solution
|-
| Tissue cracks off in cryotomy 
|
*Block too cold 
| Repair by warming slightly and adding embedding medium
|-
| Thick and thin slices 
|
*Inconsistent clamping
*Dull blade
*Incorrect blade angle
| 
*Ensure block holder and blade holder are tight
*Change blade
*Correct knife angle
|-
| Wrinkled, compressed or puckered sections ||
*Dirty or dull blade
*Tissue too warm
| 
*Clean blade
*Move or replace blade
*Cut tissue at colder temperature
|-
| Tissue advances but does not cut
| 
*Inconsistent clamping
|
*Ensure blade holder is tight
|-
| Sections roll up
| 
*Anti-roll plate is not adjucted correctly
|
*Readjust anti-roll plate
|-
| Sections thaw on the blade
|
*Blade is too warm
|
*Cool the blade
|-
| Sections stick to the anti-roll plate or blade
|
*Static in the cryostat
|
*Apply anti-static spray or anti-static gun
|-
| Sections split vertically
|
*Dirt or nick on blade
|
*Clean, move or replace blade
|-
| Sections have fine cracks parallel to the blade edge
|
*Too cold temperature
|
*Warm the tissue
|-
| Sections show signs of vibrations
|
*Specimen too loose 
*Incorrect blade angle
|
*Tighten chuck to the holder
*Change the blade angle
|-
|Stain is dull and muddy
|
*Drying artifact
|
*Put sections on glass slides immediately in fixative
|}

===Thawing===
<gallery mode=packed heights=200>
File:How to not thaw frozen block.jpg|When no more frozen sections are needed for a block, do not use  water directly on the sample, as it may get flushed away.
File:How to thaw frozen block.jpg|Rather, apply hot water to the stem of the chuck, while slightly tilting your grip of the top to apply pressure towards making the block slide off the chuck. As soon as you feel it starting to move, move away from the sink and finish sliding the block off the chuck.
</gallery>

==Reporting of intra-operative consults==
*'''Call''' the requesting clinician
*'''Verify''' that you are talking to that person, or someone who can immediately convey the diagnosis to that person. You may request to talk directly to the surgeon if a conversation is warranted.
*Tell the patient '''identity''' {{Moderate-begin}}with at least two different identifiers, such as name and date of birth{{Moderate-end}}
*{{Moderate-begin}}Ask for a '''readback''' of your diagnosis. This is particularly important in cases with multiple specimens, and when it needs to be stated that a more specific diagnosis is deferred until standard slides have been evaluated.{{Moderate-end}}<ref>{{cite journal| author=Wiggett A, Fischer G| title=Intraoperative Communications Between Pathologists and Surgeons: Do We Understand Each Other? | journal=Arch Pathol Lab Med | year= 2023 | volume= 147 | issue= 8 | pages= 933-939 | pmid=36343374 | doi=10.5858/arpa.2020-0632-OA | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=36343374  }} </ref>
*'''State''' your diagnosis succinctly. If necessary in cases with limited diagnostic tissue, you may state that additional tissue is required for a more certain report.
*{{Moderate-begin}}Make sure the clinician reads the diagnosis '''back to you'''.{{Moderate-end}}
Example:
{|class=wikitable
|
*Hello, this is from pathology. I have a frozen section result for Dr. (name of the clinician)
*This is Dr. ____, and I have a diagnosis on (patient name and date of birth){{Moderate-begin}}, if you could please read back to me after,{{Moderate-end}} the diagnosis is (diagnosis)
|}

==Frozen sectioning of suspected malignant skin excisions==
While most frozen sections can be predicted from schedules of the operating room and thereby be looked up beforehand, suspected malignant skin excisions often come from outside the main surgery department, even more indicating memorization of how to handle them.

{{Tissue selection from suspected malignant skin lesions}}

=Donor kidney biopsy=
{{Donor kidney biopsy - entire article}}

=Other frozen sections=
Although these are generally given on schedules of the operating room, any pathologist may end up suddenly covering for another one, and subsequently be presented with the frozen section case without having had the time to look it up beforehand.

In malignant or suspected malignant cases, surgical margins are generally more important than main tumor diagnosis.
*In [[lung wedge resection and lobectomy]], sample the surgical margin that is presumably closest to a tumor for frozen sectioning. {{further|Lung wedge resection and lobectomy}}
*In an [[intestine with tumor]], it is generally enough to open the intestine (avoiding cutting through a tumor unless it is corcumferantial, and grossly measuring the distances to the proximal and distal surgical margins, as well as the distances to the radial or mesenteric surgical margins. {{further|Intestine with tumor}}
*For a [[donor kidney biopsy]], generally evaluate as per local protocol. {{further|Donor kidney biopsy}}
However, for '''myocarditis''' requests (see the '''[[heart]]''' article), generally have the cardiac biopsy sent in formalin for regular H&E processing (even on weekends) rather than perform frozen sectioning, since good quality slides is the priority.

FOr further learning, focus on learning to triage, gross and sample specimens that may come for frozen sections. Microscopic evaluation is less of a priority as long as you can get assistance from seniors (including telepathology).
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==See also==
*[[Common on-call topics in clinical pathology]]
:*[[Low blood glucose]]
:*[[Suspected blasts on peripheral blood smear]]
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