Histopathology Laboratory Overview

The Histopathology Laboratory

• Aims to:
  • Process tissue samples
  • Provide accurate diagnoses
  • Archive tissue samples and reports
• Requirements:
  • Equipment and technical support for maintenance
  • Skilled histotechnologists
  • Anatomic Pathologists
  • Safety measures and waste disposal systems

Receiving of Specimen

• Complete patient and clinical data is essential for:
  • Timely evaluation and reporting
  • Contacting patient and doctor
• Outpatient referrals require the submission of:
  • Tissue samples, paraffin blocks, slides and histopathology report
  • Doctor's request for clinical impression and special preparation or fixation
• Charges are assessed based on the specimen submitted.

Specimen Rejection

• Specimens are rejected for:
  • Discrepancies between requisition and specimen label
  • Unlabeled or mislabeled specimens
  • Contaminated specimens or leaking containers
  • Lack of clinical data
  • Inappropriately identified specimens

Checking of Specimen

• Check the completeness of specimen:
  • Compare type and number of samples with surgery details
  • Check laterality (left or right side)
• Check fixation:
  • If unfixed: add formalin (surgical) or alcohol (cytology)
  • If inadequate or incorrect fixative: add or replace fixative

Specimen Collection and Containers

• Large samples:
  • Place in a wide-mouthed container or thick plastic bag with 10% neutral buffered formalin immediately.
  • Use a formalin volume 20 times the size of the specimen.
• Very large specimens:
  • Send immediately to the laboratory
• Specimens requiring cultures:
  • Put 1 part in a sterile container and send to the laboratory immediately
  • Immerse the other part in 10% neutral buffered formalin.

Logging of Specimen

• Provide a unique histopathology accession number for each case:
  • Surgical cases: S-07-000X
  • Cytology cases: C-07-000X
• Avoid using patient's name as the accession number to maintain confidentiality.
• All samples from one surgery should have the same accession number.
• This ensures homogenous evaluation and reporting.

Gross Evaluation of Specimen

• Ideally, tissue should be fixed for 6-48 hours before sectioning for optimal fixative penetration.
• Collect information on the accession number, number of sections and blocks taken per case, and embedding method.
• Samples for gross description:
  • Submitted for documentation purposes
  • Microscopic examination and histopathologic diagnoses are not performed.
• Special requests:
  • Return abortus or calculi to patient

Tissue for Gross Description Only

• Prepuce/foreskin
• Vaginal mucosa
• Scars/cicatrix
• Foreign bodies (e.g., bullets, orthopaedic implants, medical devices)