Anatomical pathology laboratory processes

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.
   • Routinue stains.
   • Special stains.
   • Immunostains.
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

Main article: 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.
  • Routine sections are cut at 3-4 micrometres.
    • 3 micrometres is considered ideal for GI biopsies and prostate biopsies.
  • Sections for Congo red are usually ~10 micrometres.
  • 4 micrometres is a recommendation for immunostains.

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

• Quality.
• Fixation.
• Laboratory information system.

External links

• Sample preparation (protocolsonline.com).