Diagnosis of Cancers with FNAC

19 October, 2020 Arush Michael

Applications of Fine Needle Aspiration Cytology (FNAC)

Most commonly used for diagnosis of palpable mass lesions such as breast masses, enlarged lymph nodes, enlarged thyroid gland, and superficial tissue masses. Also used to sample:

  • Salivary gland
  • Palpable abdominal lesions
  • Testicles
  • Prostate gland
  • Lungs
  • Retroperitoneum

Advantages of Fine Needle Aspiration Cytology (FNAC)

  1. OPD procedure requiring no hospitalization
  2. No anesthesia required unlike surgical biopsy
  3. Quick, safe, and not painful
  4. The procedure can be repeated multiple times without inconvenience
  5. Rapid results (reports available in hours)
  6. No major equipment required and it is cost-effective
  7. Cytopathologist performs procedure so first-hand knowledge of clinical findings gained so it increases diagnostic accuracy.

Materials Required for performing Fine Needle Aspiration Cytology (FNAC)

A syringe with well-fitting needle syringe holderMicroscopic glass slides suitable fixative (Coplin jar with 95% ethyl alcohol)

Method of Aspiration and Preparation of Smears

Fixing of Smears If the smears are wet fixed with 95% of alcohol they are stained with Papanicolaou and H&E stain. If the smears are dry fixed they are stained by the Romanowsky stains (Leishman’s, May-Grünwald-Giemsa)

Special and Ancillary Studies

  • Special stains: Wet fixed stains can be sued for staining with special stains for various diagnostic purposes - Alcian blue and PAS- for carbohydrate and mucinCongo red- for amyloid Bacterial and fungal stains
  • Microbiological studies- through culture for diagnosis of infection by bacteria, viruses, fungi, and mycobacteria.
  • Cell Block- to prepare sections for recognizing histologic patterns and ancillary techniques as well.  If you are diagnosed with any condition, you can now purchase medicines online in India
  • Immunocytochemical Studies- Smears or cell block sections can be evaluated by immunocytochemical stains (prepared by employing a panel of antibodies from differential diagnosis).
  • Image analysis and Morphometry- determine cellular patterns in the cell-like Nuclear/Cytoplasmic ratio; nuclear area, shape, and size.
  • Flow Cytometry- Helps in determining ploidy status and S phase fraction of tumor cells.
  • Ultrastructural studies through electron microscopy.
  • Molecular Biological Techniques to detect oncogenes in Breast cancer (ERBB-2) and lymphomas (BCL-2)

Radiological Imaging aids for Fine Needle Aspiration Cytology (FNAC)

These aids are required in order to localize non-palpable lesions in order for the technique to be properly carried out:

  1. Plain X-ray: for lesions within bones and some lesions withing the chest
  2. Image amplified fluoroscopy: visualized needle placement
  3. Computed tomographic guidance
  4. Ultrasonographic guidance

Complications and Hazards of Fine Needle Aspiration Cytology (FNAC)

There are very few complications and Hazards when compared to the advantages:

  1. Haematomas- Most common complication. Firm finger pressure after 2-3 minutes of procedure reduced this complication along with bleeding from the site of puncture.
  2. Infection- Not that significant a hazard even in transabdominal aspiration if the proper procedure of aspiration is followed and aseptic conditions maintained. Transrectal aspiration in acute prostatitis can result in bacteremia.
  3. Pneumothorax- Might result from transcutaneous aspiration of the lung.
  4. Dissemination of tumor

Precautions and Contraindications of Fine Needle Aspiration Cytology (FNAC) 

When aspiration of some sites is considered certain precautions have to be taken in some cases:

  • Bleeding disorders
  • Liver- Prothrombin time should be estimated before aspiration of the liver and the prothrombin index should not be less than 80%. There is a risk of bile peritonitis if the patient has obstructive jaundice.
  • Lung- Elderly patients with pulmonary hypertension and emphysema
  • Pancreas- In the case of acute pancreatitis
  • Prostate- Bacteraemia may be caused during transrectal aspiration in acute prostatitis
  • Adrenal- In a suspected case of Pheochromocytoma.

Cytological Diagnosis When urgently required a preliminary diagnosis can be given in an hour's time. The emphasis in Fine Needle Aspiration Cytology is on:

  • Arrangement of cells (pattern recognition)
  • Nuclear and Cytoplasmic features
  • Background morphology

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Conclusion of Fine Needle Aspiration Cytology (FNAC)

A small population of cells is sampled for the procedure so there might be a false negative result even though there are strong clinical signs of malignancy. If there is a false-negative, the test can be repeated or a surgical biopsy can be conducted in order to confirm the diagnosis.