Fine Needle Aspirate

A fine needle aspirate (FNA) is a very common diagnostic tool veterinarians use to see if a lump or mass is a malignancy. An extremely skinny needle is inserted into the mass, and a sample of the cells and fluids inside the tumor is drawn up through the needle and into a syringe. The sample is examined under a microscope. If cancerous cells are seen, further steps may be needed to get a final diagnosis, although sometimes an FNA alone can get you a diagnosis of cancer. Aspirates are not used in all cancers, particularly in cases where the lump is very hard or it’s not easy to draw fluid up. In these cases, the results may be “inconclusive.” This is a relatively inexpensive test that does not require sedation or anesthesia.