Fine Needle Biopsy

Fine needle aspiration, also known as a fine needle biopsy, is a specific test that lets doctors gather a tissue sample to test for the presence of cancer biomarkers. It is frequently performed with cancers that are suspected in the chest, breast, thyroid, or lymph nodes.

Fine needle aspirations are much less invasive than many other procedures like core biopsies or surgical biopsies.  Fine needle biopsy only needs a few minutes to complete and is able to provide a significant sample of cells for pathologists to study under magnification. Frequently an oncologist will order a fine needle aspiration if imaging shows a mass in an area where a fine needle biopsy would be effective. 

Fine needle aspirations are not usually used to diagnose mesothelioma, since other methods are needed even though they may be much more invasive, like a thoracoscopy.

With that in mind, mesothelioma may be discovered when an oncologist orders a fine needle aspiration of the lymph tissue in the neck or armpit for some other reason.

Imaging Scans Can Help Guide The Needle

A fine needle biopsy is a relatively simple procedure where the doctor inserts a long thin needle directly into a mass suspected of being a tumor and draws a small sample of tissue into the needle. Sometimes the tumor will not be directly below the skin where it can be aspirated simply. In cases like these, doctors will sometimes use scans or imaging techniques to help guide the needle or to verify its position. This can be especially helpful during the diagnosis of thoracic cancers since the tumor will often be located within the abdominal cavity and not able to be reliably targeted from outside the body.

This is not usually a painful process, but some patients will notice when the needle is inserted into their skin.

This can be mitigated with a numbing cream or another topical or local anesthetic. Complications are extremely rare but can include unexpected infection or bleeding from the insertion point. Due to the smaller needle, fine needle biopsies are much less likely to cause infection than other types of biopsy. The smaller needle also helps prevent complications like a collapsed lung.

Diagnosing Mesothelioma With Fine Needle Aspirations

While fine needle aspiration is not the standard method to diagnose mesothelioma, it may rarely discover mesothelioma incidentally. The accuracy of a fine needle biopsy as a diagnostic tool for confirming mesothelioma will depend on a few factors, namely the size of the tissue sample and the type of mesothelioma cells present.

Fine needle aspirations are rarely the definitive proof that is needed to diagnose mesothelioma. There are often several other tests needed to confirm the diagnosis. Thoracoscopy is often the test that is needed to positively confirm the diagnosis and determine the cell type of mesothelioma.

Sometimes, the pathologists will also extract RNA molecules from fine needle biopsies in order to perform cytopathologic confirmations of the diagnoses.

The main advantage to fine needle aspirations are the cost, speed, and that it is minimally invasive.