Lecture 1 Flashcards
List the steps of a typical histology workflow
- Histology specimen comes into lab – tumours, bone, kidney, spleen biopsy
- Type of investigation required
- Specimen receipt and registration (or aka accessioning) in lab – checking process
- Fixation
- Specimen grossing or cutup
- Tissue processing
- Embedding
- Microtomy
- Section drying
- Section staining (specialised techniques
- Coverslipping
- QC – checked under microscope
- Diagnostic reporting (assemble, collate to be issued to pathologist for reporting)
- Additional test request – IHC, FISH, special stains
- Slide and block filing – archives
- Specimen storage, disposal, for control use and for return to patient
- Specimen registration
- Receipt of specimens in laboratory
- Fixation
- Specimen cutup
- Tissue processing
- Embedding
- Microtomy
- Section drying
- Section staining
- Coverslipping
- Quality control
- Diagnostic reporting
- Slide/block filing
- Specimen storage
what are the benefits of a sample tracking system
- It uses barcodes to identify each specimen (unique barcode for individual specimens)
- tracks sample location in testing process via barcode labels
- Any previous testing info is identified which may indicate further additional testing required
- Alarms for incorrect specimens in process (on computer)
- Eliminates errors in labs
- Improves turnaround time (TAT) and paper reports
name hazards in histo lab
Describe a comprehensive procedure for the transportation, receipt and checking of Histology specimens and request forms on initial arrival into the department. Your answer should include examples of common anomalies and remedial action taken in the event of an anomaly (15 marks)
Transportation/delivery/receipt of specimen
- Specimen delivered via orderlies/special couriers
- Specimens for frozen section request are urgently hand delivered directly to histo staff as patient may still be in the operating theatre, therefore requires immediate follow-up
- Delivery at regular intervals or as requested by department – increases TAT
- Specimens delivered to lab in secure, robust and labelled chilly bins or equivalent with request form and other logs – so person isn’t exposed to unnecessary toxic fumes
- Log books serve as audit of delivery/receipt of specimen
- Routine histology investigations – in formalin fixative
- Transport containers/bins requirements
- Lids on specimen containers must be secured by theatre/clinic staff
- Specimen receipt procedures differs from lab to lab
Receipt of specimens in lab – pre registration anomalies fall into one of the 3 following categories
- Unlabelled – specimen or form e.g. NHI
- Mislabelled – specimen or form e.g. name
- Inadequately labelled – missing details e.g. contact details or clinicians name
Anomaly detected at specimen receipt (might be a misdiagnosis if anomaly not detected)
- All issues recorded on patients histo report – for future reference, improvements
Procedure:
- Requesting clinician contacted
- Clinician visits/faxes laboratory to correct error
- Error amended by clinician, request form is dated and initialed OR fax is attached to request form
- Specimen is registered with relevant anomaly code
- Anomaly recorded at cutup
- Routine processing therein continues
list the types of information listed on a specimen request form
Lab request from details
- Patient name
- Patient NHI number
- Patient DOH and age
- Specimen details (type)
- Theatre or clinic
- Time and date taken
- Patient encounter number
- Request for tissue return
- Name of requesting clinician
- Contact details of requesting clinician
- Patient clinical details, including specific queries (malignancy or lymphoma)
- Infectious state indicated (hep B+ve, HIV+ve, TB) – important to have these especially for people handling specimens
what actions do you take when an anomaly during specimen receipt is detected
Anomaly detected at specimen receipt (might be a misdiagnosis if anomaly not detected)
- All issues recorded on patients histo report – for future reference, improvements
Procedure:
- Requesting clinician contacted
- Clinician visits/faxes laboratory to correct error
- Error amended by clinician, request form is dated and initialed OR fax is attached to request form
- Specimen is registered with relevant anomaly code
- Anomaly recorded at cutup
- Routine processing continues
what is the meaning of a single piece workflow
Dealing with/examining one specimen at a time
FALSE
Request forms are sealed away from contact with specimen
list some methods of ensuring proper fixation is achieved
- Slicing for large specimens (longitudinally)
- Toast racking (spleen, heart)
- Perfusion (Lungs)
- Bone specimens e.g. need to be sawed
- Breast tissue requires ‘de-fatting’
what does macro description mean
Describing what the specimen looks like e.g. dimension, colour, consistency, anatomical anomalies (abnormalitites), cut surface and appearance
- Digital dictation is used
- Photography of gross specimen may be required before or during dissection (especially required for the outline of tumours in specimen)
Discuss specimen cut-up (grossing). Including information on the following:
a. Safety precautions 5 marks
b. Use of specimen cassettes 5 marks
c. Information recorded in a macroscopic/gross specimen description 5 marks
a)“single piece flow’, ‘labeling, PPE, sharps, alcohol, being aware of infectious substances + specimen carry overs (cross contamination)
- Being careful with your use of the blade because of how sharp it is
- Making sure to wear PPE especially gloves if the specimen has already been fixed in formalin as formalin is carcinogenic
- Being cautious of fresh specimens as they may be infectious, so taking care to wear gloves and other personal protective equipment
- Making sure to work in a fume hood or cut-up station to avoid inhaling toxic fumes
- Wearing safety glasses to avoid accidentally getting things like splash back of liquid or tissue specimen in your eye
b) Selected pieces of tissue are placed into a “pre-labelled” cassette which is then closed securely .
- Cassette labelling is either manual or automatic via printer
- Cassette colour designated coding system may be used for specimen types
- Microtomy instructions are recorded on the cassette
- Barcodes are displayed on cassette – helps to identify what to focus on
- Cassettes into formalin fixative ready for processing unless they require decalcification or de-fating.
Considerations:
- Thickness of specimen
- Tissue orientation (inking)
- Fragments or fragile tissue-tissue dying
- Specimen coloring
- Membranous structures-“swiss-roll”
c) dimension, colour, consistency, anatomical anomalies, cut surface appearance.
what information is captured on a blocking or embedding sheet
- Patient accessioning number
- Patient NHI or surname
- Number of tissues in embedding block
- Block identification eg. A, B, C or .1, .2 .3
- Special embedding instructions eg. Edge, end
- Special requests eg. Levels, stains
- Staff entering cutup identified
- Embedding staff identified
- Microtomy staff identified
- Tissues remained in pot following cutup? Y/N?
what is the purpose of using a sponge between tissues and when would you recommend using this
The purpose of the sponge is to prevent tissue specimens floating out, escaping the cassette, and getting lost during processing, as well as to allow the fixative to still reach the tissue as the sponge is porous. It is used for specimens that may shrink during the fixation process, or for minute specimens such as cervical tissue or prostate cores that are small in size.
what checks are put in place as QC checks once all slides have been stained prior to issuing out to pathologist for reporting
QC
- Check sections under microscope for stain and section quality
- Make sure that all stained slides have their request forms
- Match all slides against their blocks for labelling and tissue accuracy
- Case issued or signed out to pathologist for reporting
what information does a pathology report contain
A standard primary report will typically comprise of:
- Patient demographics
- Clinical details
- Macro or Gross description (including block details).
- Staff initial or name who performed the cutup.
- Microscopic description
- Diagnosis
- Snomedcoding
- Reporting Pathologist signature
Supplementary Report comprise of:
Further findings of additional work that was requested for the case. e.g.. IHC results, Cytogenetics, Flow Cytometryresults etc.
Amended Report:
When there is a change in final Diagnosis, pathologist will issue out an Amended report.
The following picture demonstrates the design of a microscope.
Clearly label the parts of the microscope
