Anatomical pathology laboratory processes

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This article gives an overview of anatomical pathology laboratory processes, simply lab processes.

Processes

  1. Accessioning.
    • Laboratory assistant:
      • Data entry - clinical history.
      • +/-Case assignment.
  2. Grossing.
    • Pathology assistant/pathology resident/pathologist.
      • Gross report.
      • Tissue blocks.
  3. Processing of tissue.
  4. Embedding of tissue.
  5. Cutting.
    • Histotechnologist.
      • Slides.
  6. Staining.
  7. Case assembly and distribution.
  8. Diagnosis.
    • Pathologist +/- pathology resident.
      • Tasks:
        • More tissue.
        • Levels/deepers.
        • Special stains.
        • Immunostains.
        • Write report.
          • Consult other pathologists - in house (internal consult) or outside (external consult).
          • Discuss with clinician.

Data elements - sequential

Prior to arrival to the lab

  • Patient identifier, i.e. medial record number (MRN) or medical care plan (MCP) number.
    • First name.
    • Middle name(s).
    • Last name.
    • Date of birth.
    • Sex.
  • Clinician identifiers.
    • Who ordered the test.
    • Where the case is sent to - ordering physician, other physicians.
  • Specimen descriptors:
    • How many parts, i.e. how many containers.
      • One container = at least one diagnosis.
      • Anatomical site of the parts, e.g. kidney biopsy.

The above information is all contained on the requisition.

Accessioning

  • Case identifier, e.g. 12:SU123.
    • 12 = year.
    • SU = surgical case.
    • 123 = case number.

Grossing

  • Description of each part:
    • Specimen dimensions, +/-weight, type of tissue.
    • Identification of gross pathology - and characterization/description.
    • Submission of tissue - in "blocks".
      • Each block is described in the gross report.

Tissue processing

  • Tissue is sent through the tissue processor - processing dependent on tissue type.
    • Date, time, batch recorded.

Embedding

  • Tissue is oriented and surrounded by wax.
    • Histotechnologist doing this is recorded.

Cutting

  • Tissue is cut from the block.
    • Pieces of tissue sent to the pathologist are tracked as "levels".
    • Who cut the tissue is tracked.

Notes:

  • The thickness of the sections can make a difference in the interpretation.[1]
    • Routine sections are cut at 3-4 micrometres.
      • 3 micrometres is considered ideal for GI biopsies and prostate biopsies.[2]
      • 4 micrometres is a recommendation for immunostains.[3]
      • Sections for Congo red are usually ~10 micrometres.


Staining

  • This is done with automated processors.
    • When and by who they are run is tracked.

Case assembly

  • Who does this is tracked.

The list of data elements

  • Case identifier, e.g. 12:SU123.
    • 12 = year.
    • SU = surgical case.
    • 123 = case number.
  • Patient identifier, i.e. medial record number (MRN) or medical care plan (MCP) number.
    • Demographics:
      • First name.
      • Middle name(s).
      • Last name.
      • Date of birth.
      • Sex.
  • Clinician identifiers.
    • Who ordered the test.
    • Where the case is sent to - ordering physician, other physicians.
  • Specimen descriptors:
    • How many parts, i.e. how many containers.
      • One container = at least on diagnosis.
      • Anatomical site of the parts, e.g. kidney biopsy.
    • Time/date.
      • When the test was ordered.
      • When the lab received the specimen.
      • When the specimen was placed into formalin.
    • Clinical history.
  • Grossing report - description of each part:
    • Specimen dimensions, +/-weight, type of tissue.
    • Identification of gross pathology - and characterization/description.
    • Submission of tissue - in "blocks" - tissue may be completely submitted (in toto) or incompletely submitted (representative).
      • Each block is described in the gross report.
      • Each block is tracked in the process.
  • Block information:
    • Number of blocks - for each part.
  • Slides - generated from the block.
    • Type of cut on each block (levels, deepers).
    • Slides distributed to the pathologist are numbered.
    • Type of stain/immunostain recorded.
  • Pathologist - elements.
    • Microscopic description.
    • Diagnosis.
    • Diagnosis comment.
    • Synoptic reports.
    • Date report signed.
    • Internal messages:
      • Clinician contacts (recorded).
      • Intradepartmental consults.
    • Addendums.
      • Consultant reports.
      • Additional tests.
      • Additional opinions that concur with the primary opinion.
    • Amendments.

See also

References

  1. Otto, MJ.; Löw, O.; Schneider, A. (1991). "The nominal section thickness--importance of their correction for morphometry.". Exp Pathol 42 (3): 129-36. PMID 1915756.
  2. LE. 20 January 2015.
  3. Magaki S, Hojat SA, Wei B, So A, Yong WH (2019). "An Introduction to the Performance of Immunohistochemistry". Methods Mol Biol 1897: 289–298. doi:10.1007/978-1-4939-8935-5_25. PMC 6749998. PMID 30539453. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6749998/.

External links