Lecture slides about tissue grossing for university students

1. Mbarara University of Science & Technology 1

2. Mbarara University of Science &
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Specimen received and taken to the grossing room
Left: specimen received with adequate formalin for size
Right: specimen received with little formalin for size

3. Introduction
• Grossing is the macroscopic description
of tissue.
• Gross description provides information
that aides the pathologist in making a
diagnosis during microscopic evaluation
of the tissue.
• It includes cutting smaller pieces of
tissue from the entire gross specimen
submitted to the laboratory.
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4. Cont’
• These pieces of tissue are likely to be more
diagnostically significant in relation to the
entire specimen, and are placed in tissue
processing cassettes for processing.
• An accurate diagnosis from the tissue is
dependent upon the correct identification
during grossing
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5. Requirements for a grossing room
• Weighing scale
• Measuring cylinder
• Camera
• Pencil and pens for
labeling cassettes
• Tissue cassettes
• Grossing ink
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• Ruler with millimeter
scale
• Magnifying lens
• 10% Neutral buffered
formalin
• Waste bins, sharps
container.
• Disinfectant (70%
alcohol)

6. Requirements for a grossing room……
• Sink with running tape
water
• Fume extractor/ fume
hood
• Surgical blades and
scalpels
• Grossing knife, scissor
and forceps
• Formalin absorbent
padr
• Water proof apron
• Mask, Gloves
• Grossing board
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8. .
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9. .
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10. Tissue blocks are placed into the cassette. Note they should not fill the cassette,
and must permit room for processing fluid circulation.
The orientation of the blocks is enhanced by a sponge securing the specimens in
sequential position
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11. General Principles/Rules of grossing tissue.
• There should never be more than one
container open at a time to ensure that
each specimen is returned to its appropriate
container so there is no chance of mix up.
• Qualified staff should do sampling of
specimen.
• The grossing of the specimen can be done
either before fixation or following it.
• It is ideal to gross larger specimen in a fresh
state and smaller following fixation.
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12. General Principles/Rules of grossing tissue…
• The sample should be described in terms of the
shape, size, color, texture and defining
characteristics of the specimen.
• This means that small biopsies, for example
endoscopic mucosal samples, may simply be
afforded a simple descriptor in the form of the
number of pieces and the size (SI units, usually
mm) of the largest piece of tissue.
• E.g ‘three pieces of brown tissue, the largest 3
mm diameter’
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13. General Principles/Rules of grossing tissue.…
• A properly completed surgical pathology
requisition form containing the patient’s
identification, age, sex, essential clinical data,
nature of operation, surgical findings, tissue
submitted and the site of biopsied specimen
should accompany every specimen.
• If more than one specimen has to be placed in
the same container, for the same patient, they
must be clearly marked, which is most readily
done by means of sutures;
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14. Cont’
• Description of additional specimens received
from the same patient must be mentioned.
• Non tissue materials such as bullets, implants,
foreign bodies should be recorded as it may
be essential for medico legal cases.
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15. General Principles of grossing tissue…
• Only labeled specimens should be accepted. The
label should be firmly attached to the body of the
container so that it cannot be separated.
• Specimen labels should not be attached to just
the lid but the body of the container as well.
• Incorrect identification of any specimen results in
the wrong diagnosis and incorrect treatment to
potentially two patients.
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16. General Principles of grossing tissue…
• Measurements of the skin surface dimensions
and depth should be documented.
• Any tissue that is small enough to slip through
the cassette holes should be wrapped in
processing tissue paper or a processing mesh
bag.
• Tissue should only be inked if it conveys
information such as orientation and margins in
excisions, or which side to embed down.
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17. General Principles of grossing tissue…
• Unusual skin surface or pigmentation should
be noted.
• Thickness of the specimen; A uniform
thickness of the specimen is an obvious
requirement for processing, but it is difficult
to achieve under conditions of insufficient
fixation or inadequate hardening of
specimen.
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18. Cont’
• The tissue thickens should ideally be 2 to 4
mm in thickness.
• Under no circumstances should any portion of
the specimen be discarded before the case is
signed out.
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19. Safety during Grossing
• All tissues must be considered potentially
hazardous and universal precautions must
be taken when grossing tissue.
• Formalin fumes are also known to be a
health hazard. It is a severe eye and skin
irritant and is toxic by ingestion and
inhalation, these can be minimized by
proper tissue handling and fixation of the
specimen before grossing.
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20. Cont’
• Adequate protective measures to protect from
infection must be undertaken such as use of
disposable gowns, gloves, facemasks and eye
gear.
• Wash hands regularly to avoid spread of
infection.
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21. Cont’
• Grossing should be under a fume hood or
safety cabinet designed to extract formalin
vapors
• Contact with chemicals should be minimized
and the protective gear should be disposed off
in correct manner.
• The laboratory personnel should clean all
instruments and working surface with a
disinfectant.
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22. General Procedure for grossing.
1.Assemble the requirements and wear PPE.
2.Correspond the identifiers on the specimen
container with those on the request form.
3.Make a general inspection of the specimen,
with identification of all of its normal and
abnormal components.
4.Macroscopically describe the specimen by
looking at and noting features like; colour,
texture, dimensions, weight, shape and unique
features like ulcerations, skin , muscle that
may be attached to specimen
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23. General Procedure for grossing…
5.Place the specimen on a grossing board
and orient the tissue in its anatomical
position.
6.The identification markers for orientation
such as sutures must be carefully
considered.
7.Surgical margins should be identified
correctly after orienting.
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24. Cont’
8.Photographs of the specimen are then taken,
before its dissected.
9.The pathologist must use sharp cutting
instrument to avoid artifacts and cuts through
the specimen to revel the inner part (cut
surface).
10.The macroscopic description of the cut
surface is then noted
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25. Cont’…
11.If the cut surface contains a tumor, its
deception like colour, texture , dimension
are noted.
12.Photographs of the cut surface are
then taken.
13.Orientation will determine the depth
of invasion of the lesion and the margins
of resection.
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26. Cont’
14.The specimen is then sampled to make
representative portions of the entire gross
specimen.
15.The sampled tissue is then placed in a labeled
tissue cassette.
16.The sampled tissue should be of 2-4 mm.
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27. Cont’
17. The tissue cassettes are then covered and
placed in a specimen 10%NBF ready for
processing
18. The working area and instruments are
cleaned after grossing..
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28. Note
1.At no point should tissue dry during
grossing
2.Contamination of the specimen can occur
anytime during the handling of the
specimen, for example, floaters, cutting
board metastasis which must be carefully
eliminated, by washing the cutting tools and
grossing board with running tape water
before cutting another specimen.
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29. Cont’
• 3.Tissue samples dissected from the main
specimen should be immediately placed in
tissue cassettes with surface to be sectioned
facing down wards, so that it is embedded
correctly.
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30. These cassettes are over-loaded.
If processing goes ahead the
specimens will be distorted and
it is likely that the processing will
be incomplete
These illegible cassette labels
are totally unacceptable
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31. Specimen Orientation during Grossing
*Right breast
lumpectomy
Received
fresh
*Suture
identification
(long lateral
and short
superior) and
specimen
orientation
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32. Specimen Painting/Inking
Margins
identified and
painted
*Anterior yellow
*Superior blue
*Posterior black
*Inferior red
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33. The purpose of inking during grossing
1. To determine the margins of the specimen.
2. Indicate specific areas of interest to the
pathologist
3. To indicate the mode of embedding.
4. Maintain the anatomic orientation of the
specimen. Inks of different colors designating
each of six specimen margins (superior, inferior
,medial, lateral, anterior and posterior) can
ideally be used to do this.
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34. Note
• Inking cut surfaces of tissue one color will help
in embedding to determine which surface
should be embedded down, where inked
surfaces will meet the blade first during the
microtomy process.
• Inking is typically reserved for excisions.
• Inking margins on biopsies is not required
since a second procedure is anticipated based
on the diagnosis of the biopsy
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35. Formalin Fixation
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36. Specimen Slicing/bread loafing
Specimen
serially
sectioned
*Lesion
identified
*Margin
evident
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37. THE END
Thank you
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38. Reference
1. World Journal of Dentistry, April-June2010;1(1):35-
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2. Handling and Grossing of Large Breast Specimens
Anita Bane MB, BCh, FRCPath, PhD ,Juravinski
Hospital & Cancer Centre McMaster University
3. UCI Histopathology laboratory Standard Operating
Procedure, GROSSING/CUT UP 2017.
4. Bancroft’s Theory and Practice of Histological
Techniques, seventh edition 2012
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