FNAC, Fine needle aspiration Cytology (FNAB, Fine needle aspiration biopsy)

Fine needle aspiration cytology (FNAC)

Sample sites for Fine needle aspiration Cytology

1. FNA sample may be obtained from:
   1. All parts of the body.
      1. Lymph nodes.
      2. Breast.
      3. Liver.
      4. Respiratory tract.
      5. Oral cavity.
      6. Thyroid.
      7. Genital Tract.
      8. The most common sites are the breast, thyroid, and palpable lymph nodes.
2. FNAC is an inexpensive and less traumatic procedure.
3. FNA has good results with the help of ultrasound in the Liver and other abdominal masses.
4. FNA may be done with the help of a CT scan, mammogram, or ultrasound-guided.

Indications of Fine needle aspiration Cytology

1. FNA material gives a cytological diagnosis of benign or malignant lesions.
2. FNA has excellent results in palpable lumps like breast or superficial masses.
3.  FNA material may be subjected to bacterial examination.
4. FNA is recommended in areas suspected of cystic fluid, nodules, lumps, and enlarged lymph nodes.

Procedure for Fine needle aspiration cytology (FNAC)

1. This procedure is performed with local analgesia or without it, and 25 g needles take samples from the suspected area of the tumor (Our experience is with 25 G needle, and we get adequate material). But most people use a 22/23 G needle.
2. We made the smear and air dry it before staining.
3. In the routine, we use Field stain.
4. Also, we do not give negative pressure unless we see poor yield. Most of the time, enough material comes without any aspiration.
5. After the procedure, separate the needle.
6. Create negative pressure in the syringe and connect the needle.
7. Push the material on the slide.
8. Spread the material with another slide.
   

   FNA procedure to fix a lump

   

   FNAC procedure

Important facts

1. This is one of the best tools for diagnosing tumors in expert hands.
2. FNA is a procedure to obtain diagnostic material for cytologic (Cells) study.
3. FNA causes minimal trauma to the patient.

Advantages of FNA

1. It is economical.
2. No anesthesia is required.
3. No need for hospitalization.
4. It is less painful.
5. It is less invasive.
6. It takes less time as compared to tissue biopsy.
7. Results are satisfactory in the expert hands.

Reporting

1. The results can be reported as:
   1. Atypical.
   2. Suspicious of malignancy.
   3. Positive for malignancy.
2. There are the following possibilities.:
   1. Infectious condition. There will be characteristic cellular components like poly, lymphocytes, and histiocytes.
   2. Benign conditions. There are characteristic benign cellular changes like uniform nuclei and normal N/C ratio.
   3. Malignant conditions. The cellular changes are typical of malignancy, like bizarre cellular appearance and changed N/C ratio, etc.

Reporting of Thyroid FNA

1. FNA of thyroid differentiates between thyroid cyst or tumors.
   1. It can be done with the help of an ultrasound.
2. There is a Bethesda reporting system that classified the result into 6 categories.
   
   1. Nondiagnostic or unsatisfactory.
   2. Benign lesion.
   3. Atypical or undetermined significance or follicular lesion of undetermined significance.
   4. Follicular lesion or suspicious for follicular neoplasm.
   5. Suspicious of malignancy.
   6. Malignant.

Reporting of Breast FNA

1.  It is the aspiration of the breast mass for cytologic examination of the aspirated material.
   

   FNA breast procedure

2. FNA breast result:
   1. It is about 1% false-positive results.
   2. There are 5% to 10% false-negative results.
   3. It gives good results in experienced hands.
   4. It will give good results to the experienced pathologist.
3. If there is a fluid, that will indicate a cystic lesion.
4. FNA will differentiate between benign or malignant smears.
5. The FNA is  reported as follows:
   1. Insufficient yield.
   2. There is a benign lesion.
   3. Atypical, probably benign lesion.
   4. Suspicious, probably in situ or invasive carcinoma.
   5. Malignant lesion.

---