Patient Education
Frequently Asked Questions (FAQs)

Fine Needle Aspiration (FNA) 

  1. What is a Fine Needle Aspiration (FNA)?
  2. What are the advantages of FNA?
  3. Who performs the FNA?
  4. What do I have to do to prepare for an FNA?
  5. Is an FNA painful?
  6. How accurate are the results from an FNA?
  7. Are there any complications of FNA?

Fine Needle Aspiration (FNA)

What is a Fine Needle Aspiration (FNA)?

A fine needle aspiration (FNA) is a biopsy technique used to sample potentially abnormal tissue. This technique can be used for patients with either superficial or deep nodules. If the lesion is deeper and cannot be felt, imaging techniques, such as an ultrasound or CT, can be used to localize the lesion for FNA. Using sterile technique, a small needle is introduced into the mass and quickly moved back and forth to remove cells. This may be performed multiple times. The cells are placed on glass slides, stained, and examined under a microscope in order to provide a diagnosis. The pathologist or cytotechnologist may review the glass slides at the time of the procedure to decide whether or not additional samples are needed [this is called a rapid on-site adequacy assessment]. Depending on the type of cells present, additional tests may be performed to determine the final diagnosis.
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What are the advantages of FNA?

FNA is a rapid procedure with minimal discomfort for the patient. The actual procedure takes only 10-20 minutes, but the entire process can take up to an hour or more if imaging or rapid on-site adequacy is necessary. Rapid on-site adequacy assessment reduces the chance that the biopsy will need to be repeated by ensuring that diagnostic material is present. This may save the patient an additional trip back to the doctor’s office or hospital. Since FNA is minimally invasive and it uses a very small needle, it is generally well-tolerated and typically requires little recuperation following the procedure. Results are usually available within a few days.
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Who performs the FNA?

FNA is usually performed by a trained physician. Rapid on-site adequacy assessment, if available, is performed by a pathologist or certified cytotechnologist. All of the slides and additional test results, if necessary, are examined by a pathologist, who gives a final diagnosis. This information is typically written in a report and given to the treating physician, who will inform the patient of the findings.
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What do I have to do to prepare for an FNA?

If the site to be biopsied is superficial (can be felt), no preparation is needed. Discuss with your doctor beforehand if you are taking aspirin or other blood thinners, have a history of a bleeding disorder, or have low platelets. If the nodule or mass is deep and requires imaging to be visualized (for example, in the lung), you will receive pre-procedure instructions either from radiology or the team performing the FNA.
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Is an FNA painful?

One of the advantages of FNA is that it is a relatively pain-free procedure. For superficial lesions, anesthetic (such as lidocaine) is typically not necessary. The needle used is smaller than the needle used to draw blood. Patients feel a “poke” during the initial entrance of the needle after which a sensation of pressure is most commonly described. Biopsies of deeper locations, visualized by imaging techniques, may require sedation and/or anesthetic. Sedation is not indicated for FNAs of superficial or palpable (‘feel-able’) masses performed in the clinic or doctor’s office.
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How accurate are the results from an FNA?

FNA is a quick and accurate way to determine the cause of the abnormal nodule or mass. Possible causes include infectious, inflammatory, and cancerous diseases. Often the FNA diagnosis will provide all of the information the clinician needs to determine treatment. In some cases which are usually related to the nature of disease, further diagnostic testing, either by repeat FNA or other tissue sampling technique, may be necessary.
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Are there any complications of FNA?

Any time the skin is broken there is a chance of infection. To minimize this risk, the skin is cleaned prior to the procedure and sterile needles and syringes are used for each sampling pass. Bleeding, usually very minimal, is controlled with pressure after the needle is removed. A Band-Aid is usually placed over the FNA site when the procedure is finished. Slight bruising and mild soreness afterward are common. After the procedure, the patient can return to their normal activities without any restrictions. As with any health concern, it is best to call your doctor to report any unexpected post-procedure developments, such as moderate to severe pain, swelling, heat, or numbness, and to proceed to the emergency department if symptoms are severe.
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