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))

Before cutting

  • Confirm that the patient identity on the specimen container matches the identity that will be applied to the gross description and cassettes.
  • 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.[notes 4] Excisions made by laser do not need inking on the excision surfaces, since the coagulated surface can be easily identified in the microscope.[1]
  • Black is generally the best ink for both gross identification and microscopy, but should not be used on lung specimens.
  • Blue and green are great for microscopy, but are often messier to apply and can be visually difficult to distinguish from black.
  • Red is most difficult to see under the microscope, and should only be used as a last resort.
  • (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.)[2]
  • 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.)[3]
  • 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 5]

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. Inking will specify the serosa or resection margin in later histopathologic evaluation.
  5. Thicker slices may not become adequately fixated in formalin.

Main page

References

  1. Monica Dahlgren, Janne Malina, Anna Måsbäck, Otto Ljungberg. Stora utskärningen. KVAST (Swedish Society of Pathology). Retrieved on 2019-09-26.
  2. Monika Roychowdhury. Grossing (histologic sampling) of breast lesions. Pathologyoutlines.com. Topic Completed: 1 August 2012. Revised: 19 September 2019
  3. . Gross Pathology Manual By The University of Chicago Department of Pathology. Updated 2-14-19 NAC.