Transcript Cytology and Cytological Techniques - Yola

Cytology and
Cytological
Techniques
Clinical Pathology
Cytology
 The microscopic examination
of cells.
 Generally refers primarily to
cells exfoliated from tissues,
lesions, and internal
organ/tumor cells.
 A very valuable diagnostic tool.
 Is inexpensive
 Is quick and easy
 Involves little or no risk to the
patient
Cytology Continued
 Must be able to identify normal cells from
abnormal cells, and inflammatory from
non-inflammatory cells
 Disadvantage may be that some tumors
do not exfoliate cells well and therefore
may not provide and adequate sample to
examine.
Cytologic Interpretation
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May be able to diagnose
Identify the disease process
Help form a prognosis
May determine what diagnostic
procedures should be performed next
 May help with therapy options
Cytologic Techniques
 Fine Needle Aspirate (FNA)
 Fluid AspirationThoracocentesis/Abdominocentesis
 Solid mass imprinting
 Vaginal wall technique
 Cerebrospinal (CSF) Fluid Analysis
 Synovial Fluid Analysis
 Nasal Flush
General Collection
Techniques
 When possible prepare several smears
 Use stained and unstained techniques
 May use a variety of stains
 Use clean, dry slides
Scrapings
 Done on freshly cut surfaces
 Scrap lesion/tissue with clean scalpel
blade
 Place material collected on a slide and
spread
 Advantage: May collect more cells
 Disadvantage: More difficult to collect
and only able to collect superficial lesions
Imprints
 May be prepared from external lesions
(ulcers)
 May be prepared from tissues excised
during surgery or necropsy.
 Easy to collect
 Disadvantage: May only collect few cells
and may contain contamination
Solid Mass imprints
 Cut mass in half
 Blot dry
 Need to remove blood/tissue
fluid from surface
 Use sterile gauze or other
absorbent material
 Excess blood/fluid inhibits cells
from spreading and assuming
normal size and shape
 Touch the slide to the blotted
surface
 Stain
Fine Needle Aspirates
 Preferred method of obtaining samples from
masses.
 Avoids superficial contamination
 Very little risk to patient
 Less complications to internal organs than core
biopsy techniques
 Implantation of malignant cells along the aspiration
tract is extremely rare
 Disadvantage: May not get a good sample
because using just a small needle.
Fine Needle Aspirate
 2 techniques
 Aspiration
 Collect with 22-25 gauge needle
 Use 3-12 ml syringe
 Need slides
 Non-aspiration
FNA Aspiration Technique
 Hold mass/lymph node firmly
 Introduce the needle with syringe attached into the mass
 Apply strong negative pressure by withdrawing the plunger to
about 2/3 -3/4 of the volume.
 Do several times in same area or redirect needle.
 Stop negative pressure and remove needle from mass
 Remove needle from syringe and air is drawn up into syringe
 Sample that is in hub of needle is expelled onto slide by rapidly
depressing the plunger
 Hold needle close to slide, if too far away will result in small
droplets that dry rapidly before smear technique may be done.
FNA Non-Aspiration
Technique
 Works best for small
masses that are difficult
to aspirate.
 Works well for highly
vascular tissues
 Using a needle only,
move rapidly back and
forth (stabbing motion).
 Withdraw needle and
place syringe with air to
force onto slide.
Preparation of smears
from aspirates
 Squash prep method
 Needle spread method
 Blood smear method
Squash Preparation
 With experience, can yield excellent cytologic smears
 Aspirated material is placed on the center of the slide
 A second slide is placed over the sample to form a
cross.
 Carefully slide apart from first slide (Put down on and
pick up to move).
 Do not place excessive downward pressure to the first
slide because will cause distorted ruptured cells
 The weight of the spreader slide is sufficient to
adequately spread the cells.
Needle Spread Method
 Spread aspirate on the slide with tip of
needle.
 Pull sample out into several projections
(starfish appearance).
Blood Smear Technique
 Use if material is thick or
fluid
 After material is expelled
on slide, second slide is
held at 30-40˚angle.
 Second slide is pulled
backward until it contacts
the fluid
 Rapidly move forward like
a blood smear.
Common Problems with
FNA
 Few or no cells obtained
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Some lesions do not exfoliate cells well.
The needle may miss the site of the lesion
Timid collection
Inadequate negative pressure
 Blood contamination
 Using too large needle gauge
 Prolonged aspiration
 Failure to blot if doing imprint
Common Problems with
Preparation
 Poorly prepared slides due to thick or high cell
numbers
 Allowing material to dry on slide before squash
prep or other smear technique.
 If a large amount of material is present, spread
between two slides
 May have to do 4-5 slides form the same site in
order to get valuable diagnostic sample.
Staining Slides
 Diff-quik, Wright’s, Geimsa
 Papanicolau stains used in human Ob/gyn exams. Stains nucleus and
nuclear material better.
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New Methylene Blue stain
Air dry these slides, do not heat fix.
Use clean slides (make sure no lint on slide)
Stain immediately after air drying
Take care not to touch the surface of the slide
or smear at any time.
Medical Terminology
 Hypertrophy-an increase in cell size and/or
functional activity in response to a stimulus.
 Hyperplasia- increase in cell numbers, via
increased mitotic activity, in response to a
stimulus.
 Neoplasia- increase in cell growth and
multiplication that is not dependent on an
external stimulus.
 Metaplasia- a reversible process in which one
mature cell type is replaced by another mature
cell type (adaptive response to a stimulus)
Medical Terminology
Continued
 Dysplasia- reversible, irregular, atypical,
proliferative cellular changes in response to
irritation or inflammation.
 Anaplasia- A lack of differentiation of tissue
cells
 Less differentiated cells in a tumor is more
malignant
 Chromatin pattern- the microscopic pattern of
nuclear chromatin (the chromatin pattern
coarsens as malignant potential increases)