Fine Needle Aspiration Biopsy

There are many ways in which a doctor can biopsy potential mesothelioma tumors. Using a thin needle to extract tissue or fluid from a mass that is suspected of being cancerous is one of the least invasive, safest, and therefore, most common types of mesothelioma biopsies. Most patients getting a diagnosis will have a fine needle aspiration done first, before undergoing more invasive procedures to secure the diagnosis and confirm the presence of cancer cells.

What is a Fine Needle Aspiration?

Fine needle aspiration is a common procedure used to do a biopsy of tissue or fluid suspected to contain cancer cells. The procedure uses a fine needle, or in other words a thin needle, that aspirates, or draws in, fluid and tissue using the action of a vacuum. A fine needle aspiration is easy and quick and can be done on an outpatient basis.

This type of biopsy is also considered safe and low-risk. This is why it is often an early step in making a diagnosis for mesothelioma. It can be used to take samples of fluid from the pleura, abdominal cavity, or pericardium for help in diagnosing any type of mesothelioma. With few exceptions, it can also be used to remove tissue from a lump in any of these areas expected to be cancerous.

Blind vs Guided Needle Biopsy

A blind fine needle aspiration is a biopsy performed without imaging to guide it. This technique is most often used after a patient has had a chest x-ray to confirm that there is a pleural effusion, or a lot of fluid buildup in the pleura. Guidance is not needed to use a needle to extract some of the fluid for examination. This procedure is not perfectly accurate in diagnosing mesothelioma, but it may rule it out.

A guided fine needle aspiration is a biopsy used in conjunction with an imaging technique, most often ultrasound, but sometimes with a CT scan. The imaging helps guide the doctor to insert the needle where the suspicious tissue, fluid, or lump is for greater accuracy. Research has demonstrated that this is a much more effective technique for accurately diagnosing mesothelioma.

Fine Needle Aspiration of the Lymph Nodes to Diagnose Mesothelioma

Diagnosing pleural mesothelioma is not straightforward or simple. It is often misdiagnosed as something less serious, which puts patients at risk of lower survival rates. Studies have described cases in which a fine needle biopsy of the pleura ruled out mesothelioma, but a biopsy of the lymph nodes confirmed it. Although pleural mesothelioma is cancer of the pleura, testing tissue in the lymph nodes using a fine needle aspiration has been proven to be a more accurate way to make a diagnosis for some patients. This may be because the cancer has spread from the pleura to the lymph nodes where the cells are easier to detect.

What to Expect

It’s normal to feel nervous about any medical procedure, but a biopsy performed with a thin needle is relatively simple, quick, and not very painful. Nevertheless, it can help to understand what will happen to make you more comfortable going into this outpatient procedure.

The first thing that will happen is that the doctor or medical assistant will disinfect the area of the skin into which the needle will be inserted. This is to prevent any infection from penetrating the skin with the needle. The doctor or assistant will then likely cover the area surrounding the disinfected skin with sterile materials.

Depending on the area of the body and the size of the needle, you may or may not receive an injection of local anesthetic. This is simply a small amount of anesthetic that numbs the area to be aspirated with the needle so that you will not feel any pain as it is inserted. The numbing will cause a slight sting or pinching feeling.

If your doctor is performing a guided biopsy, there may be an ultrasound set up to image the area under the skin. This is painless and will simply allow the doctor to see exactly where the tissue to be biopsied is. This gives the doctor greater accuracy and helps make the procedure quicker.

Finally the doctor will insert a thin needle with a syringe attached into the skin. The syringe has a vacuum that pulls up fluid or tissue, or both, from the suspected tumor. The entire biopsy from start to finish should take no more than ten minutes.

After the Biopsy

A fine needle biopsy is quick and causes few side effects; complications are rare. However, you may experience some pain or swelling at the site of the biopsy. For most patients an over-the-counter pain medication is adequate to reduce inflammation and soreness and relieve pain at the site. In rare cases this type of biopsy may cause bleeding under the skin, called a hematoma, or an infection.

Biopsy Results

The time it takes to get results from a mesothelioma fine needle aspiration biopsy varies depending on the lab and the doctor. It may be up to a week before you get results. The results are usually categorized in four different ways: definitely not cancer, definitely malignant cancer, non-definitive, or the sample was inadequate to get a result.

When the results are definitely cancer or are unclear, the next step is usually to do a more invasive biopsy. If the results show that there was not enough sample, you may simply have to undergo the needle biopsy again. If the results show there is no cancer, you may choose to get a second opinion.

Fine needle aspiration is a useful technique for diagnosing mesothelioma, but it isn’t perfect. Cancer cannot necessarily be definitively diagnosed or ruled out using this technique, which is why diagnostic strategies typically include a number of steps and several procedures for the greatest accuracy.