Get Dr. Dressler's Dog Cancer Diet FREE Hi everyone,
I have been getting questions about the best way to gather info about growths in dogs. So, let’s take a look at a common technique used to accomplish this…a fine needle aspirate.
First of all, a fine needle aspirate is not a biopsy. A fine needle aspirate is a sample of the mass taken with a skinny little needle (meaning, not much to work with). The vet will disinfect the surface of the site to be aspirated, often after clipping the hair, to prevent infection. Next, a needle is introduced into the area of interest, and the plunger drawn back, creating a vacuum which draws cells into the hub of the needle. These cells are then used to make a slide for the vet or a pathologist to look at for a diagnosis.
What is good about this technique? Well, it takes about 2 minutes to do, and your dog gets to go home without sedation, anesthesia, or hospital stay. Quick, easy, outpatient…nice. This is a good technique to diagnose TYPE of growth (in my hands about 75% of the time you get this info from the path lab after submitting the slide).
How about downsides? A fine needle aspirate cannot tell if the cancer cells have moved inside the body or spread into neighboring areas. There is a little inaccuracy in this technique as well. My experience is that about 1 out of 4 of these come back “inconclusive”, meaning there was not enough on the slide for the path folks to give a diagnosis. Sometimes the vet will get a big sample, but the cells are just not the right kind to make a diagnosis (blood, connective tissue, etc.). Some tumors have a good cell yield, and others do not. Occasionally, we get an incorrect diagnosis with a fine needle aspirate.
Some dog tumors easily diagnosed with fine needle aspirates:
Lymphosarcoma/Lymphoma
Mast Cell Tumors
Histiocytomas
Lipoma
Cysts
Short story, this technique is a good, non-invasive, rough screen to get initial information. Just keep in mind the limitations…it is not guaranteed and if there is any doubt in your vet’s mind, go for the real biopsy…coming up!
Best,
Dr Dressler
About the Author
Dr. Demian Dressler, DVM is known as the "dog cancer vet" and is author of Dog Cancer Survival Guide: Beyond Surgery, Chemotherapy & Radiation. Visit his blog and sign up free to get the latest information about canine cancer. Go to http://DogCancerBlog.com.
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Keep up your informative topics/threads Dr. Dressler!
Would fine needle aspiration give any info on sebaceous cysts? Not looking for cancer (or possibly) but any benefits to that?
Lori
Hi Lori!
Yes, you can get a presumptive diagnosis of a sebaceous cyst. Usually you need to use the physical exam findings along with the info in the path report (or that the vet gets with an in-house slide examination of the aspirated contents). With these two bits of info (the appearance, shape and feel on the physical, and the microscopic appearance of the cyst contents), you can be pretty sure of the diagnosis. Sebaceous cysts produce a typical material within them that is pretty consistent.
Why bother with an aspirate of a suspected cyst? Well, one example is a situation you are very familiar with: mast cell tumors, the Great Imitators. You have a firm, spherical nodule within dog skin on physical. Is is a cyst?? Well, maybe. Could be other things too on occasion. So it becomes a probability game…how safe are we if say (I base this number on my personal clinical impression only…) 80% of masses with this appearance on an exam actually are sebaceous cysts. This means that sometimes these lumps are NOT, and just FEEL like they are.
I always recommend the safest option: get it checked out. That way we are safe not just for the 80% that are confirmed, but also for the 20% that are actually something totally different. This means that one in five are not. For every 5 dogs that come along, one of ‘em will have something possibly harmful. Since I see gobs of dogs, the 20% WILL walk into my exam room and I WILL have to deal with it. So I always recommend the safest options.
Good blog topic! Thanks!
Dr Dressler
how much does something like this cost?
fine needle aspiration cost $20 today in Vancouver BC,
and the pathology lab cost $75, total with tax about $100.
most of what was extracted was fluid. lab analysis
results will come back in about three days.
I just literally went through that. My girl has a mass on her side. When I got her in November (she is 10) she had fleas and mites, yeast and fungus, plus three swollen lymph nodes in the same area as the mass. I did what I could to up her immunities and the three swollen lymph nodes went back down. Still not knowing what the other lump was, I brought her to the vet but got an “inconclusive” result. I was told by the vet tech that it wasn’t a cyst or a lymph node, so I’m assuming it’s a mass. I will talk to the vet later. Hopefully, I didn’t wait too late for it to have spread, which may have been indicated by the swollen lymph nodes. She’ll go in for blood work Monday and surgery to remove the mass Tuesday. I’m planning on asking the vet if at that time, an aspirate can be done on the lymph nodes surrounding that area that were swollen, or if blood tests would indicate cancer had spread.
My other dog has a mole looking cyst in his ear (unusual site) that I was told by two different vets was a sebaceous cyst. He scratched it with his nail, now it has grown into a “cauliflower” shape, so I will have them remove that too.
I think the best thing I have recently done is stop smoking cigarettes around my dogs. I’m sure it has made them more susceptible to cancers.
Dear Bridget,
I think you are doing all the right things. Keep it up!
Dr D
I have a just turned 11 year old weimarer with a few lumps and bumps about a week ago I noticed a lump on her top neck the doctor did a biso and found it was just a fatty deposit. Now I took her again today because I noticed she went pee alittle on her blanket so I asked our regular vet to check that same lump to see if it had grown at all it hasn’t but this time i asked her to aspirate it and she got a little blood out of it and just a little blood out of a another lump she has. the doctor sent the work out and i have to wait to see what is going on. the vet said it need be depending on the results we would remove the lump. Now my question is why didn’t they find any blood the first time the aspirate the lump and please don’t tell me this is the end she is the love of my life. thank you for any advice you can give.
Kim
Hello Dr.
My dog (a maltese mix) has a tumor in her liver , the vet said the tumor is too big to be surgically removed , he wants to make a tru-cut biopsy of the tumor..
My dog doesnt have symptons, she eats very well, she wants to play everyday , she doesnt vomit , she’s always so happy that i cant understand!
I’m concerned about the risks of this procedure in my dog…
what is the main difference between the FNA and the tru cut aspiration?
What would you do? Thank you for any advice and i apologyze for my english (i live in Argentina)