Diagnostic cytology- FNAC for MBBS

1. Aspiration cytology
Dr. Rupinder Kaur

3. Aspiration cytology
• FNAC was initially conceived as a means to confirm
local recurrence or metastasis of a known malignancy
• Valuable in the diagnosis of inflammatory,
degenerative and neoplastic conditions
• Intraoperative cytology, imprint cytology and
intervention cytology have revolutionized this method
• It is being used as a valuable alternative or
complement to frozen section with a comparable level
of accuracy

4. Aspiration cytology
• FNAC is a simple procedure that involves passing a thin
needle through the skin to sample fluid or tissue from a
cyst or solid mass.
• The sample of cellular material taken during an FNA is
then sent to a pathology laboratory for analysis.

5. Advantages
• Simple, requires little equipment
• Minimally invasive, no anesthesia required hence safe
with minimal discomfort to the patients
• Rapid, rapidly repeatable, cost effective- OPD procedure
• Gives pre-op diagnosis
• Virtually every organ in the body is accessible to this
method. Samples can be obtained from solid tissues that
are not connected to a hollow viscus
• Sensitive and specific for diagnosing malignancy
• Diagnostic accuracy-90-99%

6. Disadvantages
• Requires practice and skills; samples obtained may not
be representative of the lesion
• Requires expertise in diagnosing the lesion; accuracy
depends upon quality of sample and smears
• Relation with the underlying tissue not possible
• Serious complications(rare): major hemorrhage,
septicemia, bile peritonitis, acute pancreatitis,
pneumothorax etc.
• May cause local tissue changes could render
subsequent histological diagnosis difficult

7. NOT A DEFINITIVE TEST ( Gold standard- Histopath)

8. Applications
• Applied for the diagnosis of palpable as well as non
palpable lesions
• Palpable lesions:
Lymph nodes, breast, thyroid, salivary glands, soft
tissue masses and bones
• Non palpable masses: ( interventional)
Abdominal cavity, thoracic cavity and retroperitoneum

10. Procedure
• Ask the patient to lie down in comfortable position
• Expose and palpate the target area
• Clean the overlying skin with rectified spirit
• Fix 10ml/20 ml of disposable syringe with attached
needle(20-25 gauge) in Franzen handle
• Fix the mass by palpating hand and insert needle into the
target area.
• Apply suction and keep changing the direction while
moving needle back and forth within the lesion

11. Procedure
• Terminate the aspiration when aspired material or blood
is visible in the hub of the needle
• Release the suction without withdrawing the needle to
equalize the pressure within the syringe
• After withdrawing the needle apply pressure for 5-7 min
on to the puncture sites
• Aspirated material is expressed on to the clean slide by
first detaching the needle and filling the syringe with air
and expressing it with pressure
• Smear are prepared as for blood smears.
• Smears are fixed and stained

16. Missing of the
target lesion
Needle within the central
necrotic/cystic/hemorrhagic
area devoid of diagnostic
material
Sampling of a dominant
benign lesion and missing
a smaller adjacent
malignant lesion
Fibrotic/desmoplastic
tissue giving a scant
cell yield
Unsatisfactory yield

18. Adjunct tools
• Cell blocks
• Histochemistry
• Immunohistochemistry
• Electron microscopy
• Flow cytometry
• Immuno -electron microscopy
• Molecular pathology -In situ hybridization, PCR etc

19. Fixatives in cytology
• Required for preventing the shrinkage of cells,
preservation of nuclear details, kill microbes, improves
optical differentiation and enhance staining properties of
the tissues and cell components
• 95% ethyl alcohol(ethanol), ether alcohol mixture,100%
methanol, 80% propanol & isopropanol and denatured
alcohol
• Coating fixatives can also be used as an alternative-
carbowax

20. Staining in cytology
• Two types of smears are prepared- wet fixed and air
dried smears
• For air dried smears use of Romanaowsky stains
(Wrights stain, Giemsa, May Grunwald Giemsa, Diff
Quick)
• For wet fixed smear Papanicolaou stain and Hematoxylin
and eosin is commonly used

21. Staining in cytology
• Air Dried Smears
• Nuclear and nucleolar
features are less
preserved
• Cytoplasmatic features
are better preserved

22. Staining in cytology
Wet Fixed Smears
• Nuclear and nucleolar
features are better
preserved
• Cytoplasmic changes
and microorganisms are
not demonstrated

23. Additional stains
Ziehl-Neelsen stain
PAS stain

24. Immunohistochemistry

25. AUTOMATED SYSTEMS
• Based on Liquid based cytology
• Commercially available fully or semi automated devices
• Make a cell monolayer on a slide after dispersion of cells
from a sample in a liquid
• Autocyte Prep/ Sure Path
• ThinPrep Processor/ Cytyc corp

27. Automated Preparation and Staining Procedures
Slide preparation processes are automated to provide high
quality and standardized results, enabling easier
interpretation and reproducibility

28. Summary
• Cytology is diagnostic method
• „It is quick, inexpensive and accurate method, with a little
risk to the patient
• „Requires good communication with the clinicians and
correlation with other diagnostic methods
• „Requires continual learning and education