Difference between revisions of "Gross processing"

From patholines.org
Jump to navigation Jump to search
m (Limited)
(35 intermediate revisions by the same user not shown)
Line 3: Line 3:
 
|author2=
 
|author2=
 
}}
 
}}
{{General notes}}
 
 
Following are general notes on selection and trimming in pathology.
 
Following are general notes on selection and trimming in pathology.
{{Comprehensiveness}}
+
{{Comprehensiveness|otherlegend=yes}}
  
 
==Before cutting==
 
==Before cutting==
*Confirm that the patient '''identity''' on the specimen container matches the identity that will be applied to the gross description and cassettes.
+
*Confirm that the patient '''identity''' on the specimen container matches the identity that will be applied to the gross description and cassettes. {{Finding-begin}}If the referral or requisition form is available, confirm the patient identity on that one as well.{{Finding-end}}
 +
[[File:Right or left renal stone.jpg|thumb|160px|For unclear or potentially ambiguous handwriting (here "Right" or "Left" renal stone), look at the referral or requisition form {{Comprehensive-begin}}and the medical record if available{{Comprehensive-end}}.]]
 +
*{{Moderate-begin}}Check for any discrepancy between the specimen description on the container and on the referral or requisition form, such as left versus right.{{Moderate-end}}
 
*Generally '''measure''' estimated volume or 3 dimensions for samples greater than 0.4 cm in greatest dimension.<ref group=notes>Specifying dimensions in 3 dimensions is generally a waste of time for specimens less than 0.4 cm.</ref>
 
*Generally '''measure''' estimated volume or 3 dimensions for samples greater than 0.4 cm in greatest dimension.<ref group=notes>Specifying dimensions in 3 dimensions is generally a waste of time for specimens less than 0.4 cm.</ref>
*Generally '''weigh'' entire organs, after having any attached tissue trimmed away if feasible.
+
*Generally '''weigh''' entire organs, after having any attached tissue trimmed away if feasible.
*{{Comprehensive-begin}}Note the color of the sample, even when unremarkable, but do not linger on deciding it.{{Comprehensive-end}}<ref group=notes>The color is generally of little consequence.</ref>
+
*{{Moderate-begin}}Note the color of the sample, even when unremarkable, but do not linger on deciding it.{{Moderate-end}}<ref group=notes>The color of gross specimens generally has very limited clinical significance.</ref>
*Generally, use '''inking''' for resection margins where cancer radicality is important.{{Ink note}} Excisions made by laser do not need inking on the excision surfaces, since the coagulated surface can be easily identified in the microscope.<ref>{{Stora utskärningen}}</ref>
+
*Generally, use '''[[inking]]''' for resection margins where cancer radicality is important. {{further|inking|linebreak=no}}
:*'''Black''' is generally the best ink for both gross identification and microscopy, but should not be used on lung specimens.
 
:*<font color=blue>Blue</font> and <font color=green>green</font> are great for microscopy, but are often messier to apply and can be visually difficult to distinguish from black.
 
:*<font color=red>Red</font> is most difficult to see under the microscope, and should only be used as a last resort.
 
 
*{{Moderate-begin}}On fatty or greasy surfaces, apply '''vinegar''' to emulsify and remove the fat, dry the specimen and then ink. Otherwise, vinegar can be used either before or after inking to "dry" it.{{Moderate-end}}
 
*{{Moderate-begin}}On fatty or greasy surfaces, apply '''vinegar''' to emulsify and remove the fat, dry the specimen and then ink. Otherwise, vinegar can be used either before or after inking to "dry" it.{{Moderate-end}}
 
*{{Moderate-begin}}Preferably '''photograph''' or make a drawing where slices have been taken.{{Moderate-end}}<ref name=Roychowdhury>{{cite web|url=https://www.pathologyoutlines.com/topic/breastmalignantgrossing.html|title=Grossing (histologic sampling) of breast lesions|author=Monika Roychowdhury|website=Pathologyoutlines.com}} Topic Completed: 1 August 2012. Revised: 19 September 2019</ref>
 
*{{Moderate-begin}}Preferably '''photograph''' or make a drawing where slices have been taken.{{Moderate-end}}<ref name=Roychowdhury>{{cite web|url=https://www.pathologyoutlines.com/topic/breastmalignantgrossing.html|title=Grossing (histologic sampling) of breast lesions|author=Monika Roychowdhury|website=Pathologyoutlines.com}} Topic Completed: 1 August 2012. Revised: 19 September 2019</ref>
Line 27: Line 25:
 
*Generelly dissect and inspect the '''entire''' specimen, while keeping relevant parts intact enough for presentation to seniors and/or maintaining orientation.
 
*Generelly dissect and inspect the '''entire''' specimen, while keeping relevant parts intact enough for presentation to seniors and/or maintaining orientation.
 
*'''Trim''' tissues for microscopy examination to a thickness of maximum 3-4 mm.<ref group=notes>Thicker slices may not become adequately fixated in formalin.</ref>
 
*'''Trim''' tissues for microscopy examination to a thickness of maximum 3-4 mm.<ref group=notes>Thicker slices may not become adequately fixated in formalin.</ref>
 +
 +
===Perpendicular versus en face sections===
 +
[[File:Perpendicular versus en face.jpg|thumb|220px|Perpendicular and ''en face'' sections]]
 +
Two major types of sections in gross processing are perpendicular and ''en face'' sections:
 +
*'''Perpendicular sections''' allow for measurement of the distance between a lesion and the surgical margin.
 +
*'''''En face''''' means that the section is ''tangential'' to the region of interest (such as a lesion) of a specimen. It does not in itself specify whether subsequent microtomy of the slice should be performed on the peripheral or proximal surface of the slice (the peripheral surface of an ''en face'' section is closer to being the ''true'' margin, whereas the proximal surface generally displays more area and therefore generally has greater sensitivity in showing pathology, also compared to perpendicular sections).
 +
:*A '''shaved''' section is a superficial ''en face'' slice that contains the entire surface of the segment.
 +
 +
==Tissue selection==
 +
When sampling sections to submit for microscopic examination, whenever you sample from something that looks abnormal, generally try to also sample from the same type of tissue that looks '''normal'''.<ref group=notes>Normal sections from the same tissue helps identifying what is histologically abnormal in the grossly abnormal tissue, versus normal individual variations.</ref>
 +
 +
==Biopsy wraps, bags and sponges==
 +
[[File:Biopsy wrap, biopsy sponge and biopsy bag.jpg|thumb|Items used for submitting specimens: (Biopsy) wrap, (biopsy) sponge, (tissue processing) cassette and (biopsy) bag.]]
 +
Put the following types of specimens in '''bags''':
 +
*'''Tiny''' specimens that need to be poured out from their containers.
 +
*'''Bloody''' specimens such as endometrial curettages or [[products of conception]]. For products of conception, chorionic villi may otherwise contaminate other specimens. Bloody specimens may stick to wraps, so generally avoid that situation.
 +
*'''Friable''' tissue such as urinary bladder biopsies.
 +
 +
Put the following types of specimens in '''bags, wraps or sponges''':
 +
*Other '''tiny''' specimens
 +
*{{Comprehensive-begin}}Any '''small''' piece of tissue where there is no leftover specimen to retake sections, since tissues occasionally get lost from cassettes, and the absence of a wrap, sponge or bag in the cassette of such cases points towards a mistake made at gross processing.{{Comprehensive-end}}
 +
Specimens must be fixed enough to be put on sponges.
 +
 +
==H&E staining urgency==
 +
{{Moderate-begin}}Even in departments where other staff are primarily responsible for determining the urgency of H&E staining of each specimen, still double-check that it is correct if you can, such as by cassette color.{{Moderate-end}} A major indication for rushing cases through H&E staining is a high risk of cancer, especially where '''immunohistochemistry''' staining will likely be performed, and the decision and types of staining will be determined by the standard H&E stain. Tissues that are generally rushed are:
 +
*'''[[Brain]]''' biopsy.
 +
*'''[[Lung]]''' biopsy.
 +
*'''[[Breast]]''' needle biopsy.
 +
*Biopsy from known '''[[tumor]]''' tissue.
 +
*Suspected malignant '''[[lymph nodes]]''', including lymphoma. However, these are generally not urgent when submitted together with a tumor, except mainly for the following (which are generally urgent):
 +
:*Pelvic sentinel lymph nodes
 +
:*Sentinel lymph nodes from known [[invasive lobular carcinoma]] (but not [[invasive ductal carcinoma]])
 +
In both these cases, the cases are rushed so that immunohistochemistry can be performed if a metastasis is not readily detected on standard H&E slides, so that it is available by the time the rest of the slides are out. Immunohistochemistry in these cases can detect micrometastases that are not readily visible on H&E stain, but are evident on cytokeratin AE1/AE3. However, if the lab stains such cases regardless of whether H&E stain shows a metastasis or not, then they do not need to be rushed.
 +
 +
==Marking cassettes==
 +
Use only hard pencil (or specially purchased histology markers), as marks made with pens, Sharpie markers, or scientific freezer-safe markers can get dissolved in tissue processing.<ref>{{cite web|url=https://unclineberger.org/pathologyservices/instructions/histopathology-services/|title=Histopathology Services|website=UNC School of Medicine|accessdate=2021-11-15}}</ref>
 +
 +
==By organ or organ system==
 +
*[[Gross processing of skin excisions]]
 +
<noinclude>
 +
{{General notes}}
 
{{Bottom}}
 
{{Bottom}}
 +
</noinclude>

Revision as of 21:11, 9 December 2021

Author: Mikael Häggström [note 1]
Following are general notes on selection and trimming in pathology.

Comprehensiveness

On this resource, the following formatting is used for comprehensiveness:

  • Minimal depth
  • (Moderate depth)
  • ((Comprehensive))
Other legend

<< Decision needed between alternatives separated by / signs >>
{{Common findings / In case of findings}}
[[Comments]]
Link to another page

Before cutting

  • Confirm that the patient identity on the specimen container matches the identity that will be applied to the gross description and cassettes. {{If the referral or requisition form is available, confirm the patient identity on that one as well.}}
For unclear or potentially ambiguous handwriting (here "Right" or "Left" renal stone), look at the referral or requisition form ((and the medical record if available)).
  • (Check for any discrepancy between the specimen description on the container and on the referral or requisition form, such as left versus right.)
  • Generally measure estimated volume or 3 dimensions for samples greater than 0.4 cm in greatest dimension.[notes 1]
  • Generally weigh entire organs, after having any attached tissue trimmed away if feasible.
  • (Note the color of the sample, even when unremarkable, but do not linger on deciding it.)[notes 2]
  • Generally, use inking for resection margins where cancer radicality is important. Further information: inking
  • (On fatty or greasy surfaces, apply vinegar to emulsify and remove the fat, dry the specimen and then ink. Otherwise, vinegar can be used either before or after inking to "dry" it.)
  • (Preferably photograph or make a drawing where slices have been taken.)[1]
  • Remove any surgical stitches from samples before microtomy.
  • (At least for larger samples, consider looking for medical imaging or biopsy reports in order to better guide the process.)[2]
  • Fix bone in formalin prior to decalcification. Use reminders so not to forget bone that is decalcifying.

Cutting

  • When cutting with the longer knives, try to cut in one stroke - do not use like a saw (continuous back and forth)
  • Generally, strive to make slices perpendicular to visible interfaces of relevant tissues.
  • Generelly dissect and inspect the entire specimen, while keeping relevant parts intact enough for presentation to seniors and/or maintaining orientation.
  • Trim tissues for microscopy examination to a thickness of maximum 3-4 mm.[notes 3]

Perpendicular versus en face sections

Perpendicular and en face sections

Two major types of sections in gross processing are perpendicular and en face sections:

  • Perpendicular sections allow for measurement of the distance between a lesion and the surgical margin.
  • En face means that the section is tangential to the region of interest (such as a lesion) of a specimen. It does not in itself specify whether subsequent microtomy of the slice should be performed on the peripheral or proximal surface of the slice (the peripheral surface of an en face section is closer to being the true margin, whereas the proximal surface generally displays more area and therefore generally has greater sensitivity in showing pathology, also compared to perpendicular sections).
  • A shaved section is a superficial en face slice that contains the entire surface of the segment.

Tissue selection

When sampling sections to submit for microscopic examination, whenever you sample from something that looks abnormal, generally try to also sample from the same type of tissue that looks normal.[notes 4]

Biopsy wraps, bags and sponges

Items used for submitting specimens: (Biopsy) wrap, (biopsy) sponge, (tissue processing) cassette and (biopsy) bag.

Put the following types of specimens in bags:

  • Tiny specimens that need to be poured out from their containers.
  • Bloody specimens such as endometrial curettages or products of conception. For products of conception, chorionic villi may otherwise contaminate other specimens. Bloody specimens may stick to wraps, so generally avoid that situation.
  • Friable tissue such as urinary bladder biopsies.

Put the following types of specimens in bags, wraps or sponges:

  • Other tiny specimens
  • ((Any small piece of tissue where there is no leftover specimen to retake sections, since tissues occasionally get lost from cassettes, and the absence of a wrap, sponge or bag in the cassette of such cases points towards a mistake made at gross processing.))

Specimens must be fixed enough to be put on sponges.

H&E staining urgency

(Even in departments where other staff are primarily responsible for determining the urgency of H&E staining of each specimen, still double-check that it is correct if you can, such as by cassette color.) A major indication for rushing cases through H&E staining is a high risk of cancer, especially where immunohistochemistry staining will likely be performed, and the decision and types of staining will be determined by the standard H&E stain. Tissues that are generally rushed are:

  • Brain biopsy.
  • Lung biopsy.
  • Breast needle biopsy.
  • Biopsy from known tumor tissue.
  • Suspected malignant lymph nodes, including lymphoma. However, these are generally not urgent when submitted together with a tumor, except mainly for the following (which are generally urgent):

In both these cases, the cases are rushed so that immunohistochemistry can be performed if a metastasis is not readily detected on standard H&E slides, so that it is available by the time the rest of the slides are out. Immunohistochemistry in these cases can detect micrometastases that are not readily visible on H&E stain, but are evident on cytokeratin AE1/AE3. However, if the lab stains such cases regardless of whether H&E stain shows a metastasis or not, then they do not need to be rushed.

Marking cassettes

Use only hard pencil (or specially purchased histology markers), as marks made with pens, Sharpie markers, or scientific freezer-safe markers can get dissolved in tissue processing.[3]

By organ or organ system

General notes edit

Further reading:

Notes

  1. Specifying dimensions in 3 dimensions is generally a waste of time for specimens less than 0.4 cm.
  2. The color of gross specimens generally has very limited clinical significance.
  3. Thicker slices may not become adequately fixated in formalin.
  4. Normal sections from the same tissue helps identifying what is histologically abnormal in the grossly abnormal tissue, versus normal individual variations.
  1. For a full list of contributors, see article history. Creators of images are attributed at the image description pages, seen by clicking on the images. See Patholines:Authorship for details.

Main page

References

  1. Monika Roychowdhury. Grossing (histologic sampling) of breast lesions. Pathologyoutlines.com. Topic Completed: 1 August 2012. Revised: 19 September 2019
  2. . Gross Pathology Manual By The University of Chicago Department of Pathology. Updated 2-14-19 NAC.
  3. . Histopathology Services. UNC School of Medicine. Retrieved on 2021-11-15.

Image sources