Gross processing

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Author: Mikael Häggström [notes 1]

General notes edit

Following are general notes on selection and trimming in pathology.

Contents

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]]
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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 2]
  • 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 3]
  • 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 4]

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 5]

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.

By organ or organ system

Notes

  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.
  2. Specifying dimensions in 3 dimensions is generally a waste of time for specimens less than 0.4 cm.
  3. The color is generally of little consequence.
  4. Thicker slices may not become adequately fixated in formalin.
  5. Normal sections from the same tissue helps identifying what is histologically abnormal in the grossly abnormal tissue, versus normal individual variations.

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.