PRELIM LEC: PRE-ANALYTICAL FACTORS, GROSS EXAMINATION Flashcards
Time interval between surgical intervention and proper fixation of the removed specimen
Ischemia Time
Ischemia Time DIVIDED INTO:
Warm Ischemia Time
Cold ischemia time
Occurs during operation when blood supply of tissue is cut
off
Warm Ischemia Time
If prolonged, ischemia will allow activation of tissue enzymes, autolysis, and degradation of proteins and nucleic acids, which affects visualization of tissues
Ischemia Time
During this period, the tissue is alive and active, but will undergo progressive metabolic stress due to hypoxia
Warm Ischemia Time
Beyond the control of the histopathology lab
Warm Ischemia Time
Interval between tissue removal from the patient and arrival in the pathology laboratory for grossing
Cold Ischemia Time
Affected by the whole surgical procedure (complexity of procedure, ability of surgeon, modality of intervention)
Warm Ischemia Time
Extensions may contribute to poor fixation
Cold Ischemia Time
If prolonged, temperature of specimen will gradually reach the external temperature, and autolysis and drying of the surface may occur
Cold Ischemia Time
All parts to be examined must be initially fixed
Pre-Analytic Fixation
Earlier fixation better preservation of tissue morphology
Pre-Analytic Fixation
Proper ratio with tissue must be observed
Pre-Analytic Fixation
** 3-5mm thick tissues** may be fixed for
Pre-Analytic Fixation
6-48hrs
5mm thick tissues and large tissues (such as limbs) must be ________, or else, fixation will not be complete and may occur only at the periphery of the tissue
Pre-Analytic Fixation
sectioned prior to fixation
Submitted specimens must be put in a container** labeled with patient’s name and specimen source/site,** and must be accompanied with a duly accomplished pathology requisition form.
Specimen Reception
Criteria for Rejection of Specimens:
a) Discrepancies between requisition form and specimen labels
b) Unlabeled, mislabeled, and inappropriately identified specimens (last resort: DNA identification)
c)** Leaking specimen containers**
d) Absent clinical data or history, and other necessary info
**1st and most important step in HP **outside the tissue processing procedures
Specimen Accessioning
Specimens are given a unique identification number (may be a barcode, for some laboratories) that will identify each specimen for each patient
Specimen Accessioning
- Also useful for ease of retrieval of specimens, slides, and blocks
Specimen Accessioning
- Indicating codes may be used for the following
Specimen Accessioning
o Surgical
o Autopsy
o Cytology
Avoid serial accessioning of similar specimen types to reduce mix-up of specimens, and cross-contamination
Specimen Accessioning
Consists of describing the specimen and placing all or parts of it into a plastic cassette, in preparation for tissue processing
GROSS EXAMINATION
One of the basis of pathologists’ diagnosis
GROSS EXAMINATION
Involves selection of elements that appear to be of clinical significance for histologic examination
GROSS EXAMINATION
cleaned before and after use (to avoid carryover)
Cutting Tools
Cutting Tools:
o Scissors
o Forceps
o Blade holders
o Blades - disposed in sharps container
Specimens only requiring transfer from container to tissue cassette. No dissection required
CATEGORY A
Gross Table or Gross Workstations:
Sink
Tabletop
Water supply
Irrigation system
Fume extraction/ventilation system
Water disposal unit
Specimen Categories:
- A
- B
- C
- D
- E
May need to be placed in filter paper first before placing in cassette because of their small size
CATEGORY A
CATEGORY A SPECIMEN EXAMPLE
e.g. endometrium, colonic series, breast core biopsies
Specimens requiring transfer and routine sample dissection: sampling, counting, weighing, or slicing
CATEGORY B
CATEGORY B SPECIMENS EXAMPLE
e.g. small lipoma, small skin biopsy, cervical LLETZ (Large Loop Excision or Transformation Zone)
Simple dissection required with sampling needing a** low level of diagnostic assessment** and/or preparation
CATEGORY C
CATEGORY C SPECIMENS EXAMPLE
e.g. Prepuce (fore skin in male) / Folds in clitoris (female) Gall bladder, hemorrhoids, appendix
Dissection and sampling required needing a moderate level of assessment
CATEGORY D
CATEGORY D SPECIMENS EXAMPLE
e.g. Pigmented skin lesions, skin w/ markers, large intestine (Crohn’s), large glands tumors
Specimens for Gross Description Only
(because disease is not histologic level):
Specimens requiring complex dissection and sampling methods
CATEGORY E
CATEGORY E SPECIMENS EXAMPLE
e.g. thyroid, breast cancer, testis (seminoma), uteri
Identify orientation markers used by surgeons, if available
Describing Specimens and Gross Description
Identify the specimen. Note and verify all anatomical structures.
Describing Specimens and Gross Description
used to identify and orient the specimen’s
components, distinguish samples, for embedding instructions
Inks
– indicates laterality
Nicks
represented by LL: long lateral; or SS – short superior
Sutures
Describe all notable characteristics:
type of specimen, shape,
color, texture, consistency, dimensions, weigh
of intact organs are rounded to the nearest 0.1g. (In some cases, weight is more important than histopathologic characteristics. Examples are hyperplastic tissues.)
Weight
(length, width, depth) are rounded to nearest 1.0 cm. For multiple pieces, indicate size of the largest piece.
Dimensions
Taking a representative sample of the tissue.
Sectioning
Cut serially about 2 mm thick to look for small
lesions. Lesions are then sampled for
histologic exam. Filter paper may be used in
wrapping small samples
Small specimens
Cut at an interval of 1 cm thickness (termed
as breadloafing) to ensure that pathologic
areas or tumoral areas are identified
Large specimens
Specimen must fit easily into the standard cassette, which
measures
3 x 2.5 x 0.4 cm
Indicate number of sections and blocks on the gross description
sectioning
When possible, edges of tissue should be
squared
are embedded in the cassette. They should labelled with accession number using pencil. Markers and pens will dissolve upon processing.
Paper tags
not more than 0.3 cm to allow for closing of cassette and fixative penetration
Thickness
if printed, ___ must be used.
dot matrix
Original containers with specimen are saved until case is signed out (backup evidence in cases of discrepancies)
yasss
is fixed first before grossed
Tied at the Circle of Willis and suspended
Must not touch side of container to avoid deformity
In 10% NBF for 2-3 weeks
Brain
Base (the area where cautery arteries are located) is
always inked.
Colon Cancers Polyps
sides are trimmed away from the stalk,
and stalk is placed in a separate cassette
Large polyps
Bisected and placed in one cassette
Small polyps
- Vertical orientation is always maintained (using markers)
- Punch biopsies are submitted whole
- Tissues greater than 4mm are dissected
- Skin ellipses: serially cut along the short axis at 2 to 3 mm interval.
The two most distal sections or tips are submitted in two separate cassettes. Remainder is submitted in one or more cassettes
Dermatologic SPX
Inject fixative first then gross.
Eyes
Wash in running water then immerse in tissue softeners
Hard Tissues
Must be cut open longitudinally and fixed with cottons inside
Hollow Structures
most important component of tumor resections because they are essential for prognosis and planning therapeutic options
- Should be received fresh and not immersed in formalin
- Node is bivalved, and entirely submitted
Lymph Nodes
usually first lymph node to be involved
during metastasis. Entirely submitted. However, large specimens may be bisected, and submitted in one or two cassettes
Sentinel lymph nodes
Note for weight, size of breast and axillary dissection, skin ellipse, nipple scar, basal margins
Mastectomy
Additional processes such as IHC, flow cytometry, cytogenetics and molecular genetics is often done. These may require fresh, frozen, or specially processed tissues
Pediatric SPX
Specimen with Tumor
- Identify:
► Site & size of tumor
► Location & structure invaded by tumor
► Vascular invasion
► Presence of lymph node
► Distance from resection margin
- Aka “gross worksheet”
- Guides histotechnician in assuring that all blocks are processed
- Must be properly filled up; filled for future reference
- Contains the following:
- Accession number
- Number of sections and blocks
- “Comments” column (for special requests & etc.)
- Gross description
Specimen Worksheet