What Is a Fine Needle Aspiration (FNA) Biopsy for Lung Cancer?

A fine needle aspiration (FNA) is one option for a lung biopsy, which is done to confirm or rule out the presence of lung cancer. It involves using a thin needle to extract tissue from the lung so its cells can be examined in a lab. Also referred to as a percutaneous biopsy or a transthoracic biopsy, an FNA is the least invasive way to get a tissue sample for analysis.

It's not always possible to perform an FNA, however, and it sometimes doesn't allow doctors to obtain sufficient tissue for testing. When it is an option, a fine needle aspiration will be quickly analyzed by a pathologist and enable you to know whether you need to take the next step and discuss lung cancer treatments with your doctor.

Purpose of Test

An FNA biopsy is performed to determine if a tumor, found during a chest X-ray or computed tomography (CT) scan, is benign (non-cancerous) or malignant (cancerous).

An FNA may be done to evaluate a:

  • Lung nodule: A spot in the lung that is 3 centimeters (cm) in diameter or less
  • Lung mass: An abnormal spot that is greater than 3 cm

Depending on your condition, an FNA may be preferable to an open lung biopsy, which requires a surgical procedure to open the chest, push aside the ribs, and remove a sample of the tumor.

Risks and Contraindications

While FNA does offer many advantages, there are some downsides to consider.

False Positives

A fine needle aspiration is very sensitive in diagnosing lung cancer, but researchers have found that it sometimes delivers false-positive results. This means that it indicates that cancer is present though there is no malignancy.

In one study, the specificity of the technique was 81%, meaning that there was an incorrect diagnosis around 19% of the time. To counter this possible misreading, doctors usually use a combination of tests to diagnose lung cancer.

Insufficient Testing

A study comparing tissue samples taken at hospitals showed that in 20% of cases, the tissue samples obtained were not sufficient enough to allow doctors to do a proper analysis. When this occurs, it not only requires you to undergo another procedure, but it can lead to a delay in diagnosis as well as treatment.

The number of tests that are now ordered by oncologists to confirm staging, genetic mutations, and other important information to determine treatments may require more significant tissue samples than doctors can obtain via a fine needle aspiration. Discuss this with your doctor before arranging your FNA.

Complications

In general, this procedure is safer than other methods of getting a specimen for testing. Possible complications of an FNA that you should be aware of include:

  • Bleeding: Your doctor will talk to you about any medications you take that can increase bleeding, including some nutritional supplements and herbal preparations. Older adults are most at risk for bleeding (pulmonary hemorrhage).
  • Collapsed lung: Some degree of an air leak, known as a collapsed lung or pneumothorax, has been reported in up to 54% of people undergoing an FNA. If a pneumothorax occurs, a chest tube may need to be inserted. At times, it will need to be left in place for a duration until your lung re-expands and the issue has resolved.
  • Tumor seeding: There is a hypothetical risk that FNA could result in tumor seeding. The thought is that some of the cells removed through the biopsy could be left behind along the course of the needle as it is removed. If this occurs, the cells could grow in the spot in which they were deposited and start a new tumor. The risk of this has been studied most widely in breast cancer cases, but there are concerns that it may be a complication related to lung cancer biopsies as well.

Before the Test

As you are prepared for your FNA, you will meet with your doctor to discuss the procedure. Let your doctor know about any over-the-counter medications or supplements you're using.

Timing

An FNA is an outpatient test. The needle biopsy takes about half an hour to an hour to complete. After the sample is taken, you may be taken to a room to be observed for several hours before being discharged.

Food and Drink

Usually, food and drink are prohibited for eight hours before your biopsy. Talk with your doctor about taking routine medications or sips of water.

During the Test

The process of inserting the needle and gathering the sample tissue is brief, but there are steps that need to be taken to make sure the procedure goes smoothly.

Procedure

A fine needle aspiration may begin with you lying on a table. A chest X-ray or chest CT scan may then be taken, which will allow your doctor to find the exact location of the node or mass. If imagining is not required, you may be positioned upright in a seat with your arms resting on a table in front of you.

In most instances, only a local painkiller or anesthetic is used. This is injected into the chest area where the needle will enter. A sedative may also be administered to help you relax during the procedure, but you will remain awake throughout the process.

The spot where the needle will enter will be sterilized, and the doctor will prepare to take the sample.

During the biopsy, you will need to remain still. Your doctor will ask you to refrain from coughing, but you may be asked to hold your breath several times during the procedure.

Start to finish, your FNA will follow these steps:

  • A small incision is made in your skin.
  • The long, thin biopsy syringe needle is inserted into the node or mass.
  • Pulling up on the syringe needle, a small piece of tissue is removed.
  • The doctor pulls the needle out of the incision area.
  • Pressure is applied to the wound to stop any bleeding; dressing is placed over the wound.
  • An X-ray or other imaging scan may be done to monitor for complications.
  • The biopsy sample is sent to the lab, and results of the analysis will be sent to you within a few days.

Your doctors will take steps to minimize the risk of a collapsed lung following your FNA. This includes instructing you not to move, talk, cough, or breathe deeply during and immediately after the procedure. They will also take care to make as few punctures as possible.

After the Test

You will be taken to a room to be monitored for several hours before being discharged. As the local anesthetic wears off, you may feel soreness where the biopsy was done. You may experience hemoptysis, coughing up blood, but this should be minimal. Within 12 to 48 hours of being discharged, these symptoms should significantly lessen or disappear.

You should be able to remove your bandage within a day of the procedure, and you will be able to bathe or shower as normal at that time. Limit physical activities such as lifting heavy items or climbing for at least two days after your biposy, or for as long as your doctor advises.

Even though great care is taken to minimize your risk of a collapsed lung, you still need to watch for signs of one, including:

  • Shortness of breath
  • Increased heart rate
  • Sharp pain in the chest or shoulder
  • Blue discoloration of the skin

If you experience any of these symptoms after being discharged, contact your doctor and go to the emergency room.

Interpreting Results

The tissue cells that are removed will be sent to a pathologist to evaluate under a microscope. You can expect results within two to three days of the test, possibly sooner.

The report may include a description of the tissue sample that was taken. There may be a details regarding how the cells from the sample appear under the microscope.

Finally, the report will include a diagnosis: malignant or benign. Recommendations for follow-up tests may be included. This is especially likely if you receive a positive result, as it may not be correct and should be confirmed.

Follow-Up

In the case of a positive diagnosis, you and your doctor will meet to discuss next steps in terms of additional testing and, possibly, options for starting lung cancer treatment.

For positive biopsies, cytology testing may also be performed on the samples to determine the type of cancer. Further testing will also be needed to determine the stage of your cancer.

Other Considerations

While fine needle aspiration is a good, non-invasive way to learn more about suspicious spots on imaging, the procedure is not always possible. Some masses or nodules may not be accessible with a needle due to their location, for instance. In these cases, you will need to consider other biopsy options.

If you do undergo an FNA, remember that a positive result will need to be confirmed by other tests. You may also want to consider getting a second opinion before making any decisions regarding treatment.

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