Fine Needle Aspiration

Fine needle aspiration is a type of biopsy procedure. During the procedure, a small needle is inserted into the region of concern, and a sample is collected from a microscope, slide or sterile container.  These samples can help make a diagnosis, e.g. of infection or cancer.

• Fine needle aspiration is most commonly performed on a lump or abnormal-appearing organ. These changes may be identified on physical examination or an imaging test such as an ultrasound or CT scan.
• Fine needle aspiration may also be performed on:
  • cysts (fluid-filled lumps)
  • nodules or masses (solid lumps)
  • enlarged lymph nodes
• Without a biopsy, it’s difficult for a veterinarian to know what these abnormal areas contain.

• Your cat is likely to be under sedation or anaesthesia for this process. This is not because it is painful but to keep them still during the procedure.
• Their fur is clipped, and the area is cleaned.
• We will sometimes use a local anaesthetic on the skin.
• Ultrasound can be used to help locate the region for fine needle aspiration.
• A thin needle is attached to a syringe and inserted through the skin into the abnormal area.
• A sample is suctioned (aspirated) into the needle and syringe and then placed on a microscope slide and/or sample pot.
• Several needle insertions may be required to ensure that the sample is adequate.

Fine needle aspiration itself is usually a short procedure, less than 10 minutes to 20 minutes, depending on the number of samples required.

• If your cat has been sedated, it may be a little groggy afterwards, but this should only last for a few hours.
• Rarely there may be a little bruising at the site.

• Serious complications after fine needle aspiration are rare.
• Minor bleeding under the skin at the biopsy site can occur.
• Sometimes, bleeding can occur from tumours or tissues with blood vessels.

• A fine needle aspirate is an effective tool in evaluating and diagnosing suspect lumps or masses.  It is minimally invasive, however, compared to a surgical or trucut biopsy, samples are very small and fine needle aspiration biopsies do require some expertise to perform and interpret.
• Because an FNA biopsy can only sample a small number of cells from a mass or lump, there is a risk that any abnormal cells may be missed and not detected.

The samples are either assessed in the hospital or sent to a laboratory. The material is examined using a microscope after it has been prepared and stained so that the cellular material can be seen.

Results are received within 24-48 hours, and we will contact you as soon as we receive them.