Fine-Needle Aspiration & Biopsies

Hey, guys, My name is Dr. Lara here at Heron Lakes Animal Hospital. Today I'm doing a quick video about the difference between what's called an FNA or fine needle aspirate versus a biopsy. So the main difference between a fine needle aspirate, a biopsy, a fine needle aspirate will give you some cells of what it is. A lot of times what it is they're trying to diagnose. Most of the time, if your dog has some sort or cat has some sort of bump or lump or mass like a fe. In fact, we usually will stick a needle in it hoping to go ahead and get some cells. Sometimes we don't get cells even when we use big needles. And so if you guys come over here, one of the things that you'll see is this is what's called a 25 gauge needle. It's a relatively small needle. And then what I'm going to do is I'm going to show you a 18 gauge needle. And sometimes depending on who's collecting the sample, they may go ahead. And so you can see a big difference between this needle and the other needle. People sometimes will use the bigger needles hoping to get a better chance of a good sample. Not always necessary. And so the thing at the end of the day is you're usually not going to get a definitive diagnosis with doing a fine needle aspirate. There are a few occasions, like a melanoma, like a mast cell tumor, where you will get a definitive diagnosis, but you will not figure out how aggressive it is based on what we call a mitotic index. That's how fast it's reproducing. Okay. You can only see certain kinds of cells. To get a definitive diagnosis, you usually need what's called the cellular architecture. So that means how the cells line up, if they're like this, like this, like this, like this, and what kind of cells they are. So usually that's going to require a biopsy. Sometimes you can do what's called a punch biopsy. And so I have a couple of different punches here. This is an example of a punch biopsy. So you can see how much bigger this is versus the needle. And then we have other biopsies where these are even bigger. Okay. Now, the other way of collecting a biopsy sample is by going ahead and making an actual cut into the patient's skin where the growth is and collecting a sample and sending that off to the lab. Usually that's going to take a minimum of about four to five business days. So don't anticipate a result very, very quickly because the sample has to be prepared and then has to be read by the pathologist. If you go somewhere and they tell you they're doing a fine needle aspirate, they are majority of time assuming what it is based on the results, they cannot give you a definitive diagnosis. That's my big pet peeve. Be aware the difference between a fine needle aspirate and a biopsy. If you guys have any questions about this particular topic, please leave it in the comment box. If you found it helpful, give us a thumbs up. Share it with somebody you think might need it, and subscribe so that you can find some other helpful information for you and your family members in the future. Thanks for watching and have a great day.