Fine needle aspirates to diagnose dog cancer?
Dr. Demian Dressler is internationally recognized as “the dog cancer vet” because of his innovations in the field of dog cancer management, and the popularity of his blog here at Dog Cancer Blog. The owner of South Shore Veterinary Care, a full-service veterinary hospital in Maui, Hawaii, Dr. Dressler studied Animal Physiology and received a Bachelor of Science degree from the University of California at Davis before earning his Doctorate in Veterinary Medicine from Cornell University. After practicing at Killewald Animal Hospital in Amherst, New York, he returned to his home state, Hawaii, to practice at the East Honolulu Pet Hospital before heading home to Maui to open his own hospital. Dr. Dressler consults both dog lovers and veterinary professionals, and is sought after as a speaker on topics ranging from the links between lifestyle choices and disease, nutrition and cancer, and animal ethics. His television appearances include “Ask the Vet” segments on local news programs. He is the author of The Dog Cancer Survival Guide: Full Spectrum Treatments to Optimize Your Dog’s Life Quality and Longevity. He is a member of the American Veterinary Medical Association, the Hawaii Veterinary Medical Association, the American Association of Avian Veterinarians, the National Animal Supplement Council and CORE (Comparative Orthopedic Research Evaluation). He is also an advisory board member for Pacific Primate Sanctuary.
Updated: April 4th, 2019
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
Dr. Demian Dressler is internationally recognized as “the dog cancer vet” because of his innovations in the field of dog cancer management, and the popularity of his blog here at Dog Cancer Blog. The owner of South Shore Veterinary Care, a full-service veterinary hospital in Maui, Hawaii, Dr. Dressler studied Animal Physiology and received a Bachelor of Science degree from the University of California at Davis before earning his Doctorate in Veterinary Medicine from Cornell University. After practicing at Killewald Animal Hospital in Amherst, New York, he returned to his home state, Hawaii, to practice at the East Honolulu Pet Hospital before heading home to Maui to open his own hospital. Dr. Dressler consults both dog lovers and veterinary professionals, and is sought after as a speaker on topics ranging from the links between lifestyle choices and disease, nutrition and cancer, and animal ethics. His television appearances include “Ask the Vet” segments on local news programs. He is the author of The Dog Cancer Survival Guide: Full Spectrum Treatments to Optimize Your Dog’s Life Quality and Longevity. He is a member of the American Veterinary Medical Association, the Hawaii Veterinary Medical Association, the American Association of Avian Veterinarians, the National Animal Supplement Council and CORE (Comparative Orthopedic Research Evaluation). He is also an advisory board member for Pacific Primate Sanctuary.
Dear Dr. Dressler,
My 9 year old basset had his senior and one year post amputation check-up last week. Last year he was diagnosed with bone cancer. He has done magnificently well this past year and is in great spirits, acts like a 2 year old. Your survival guide is our bible throughout this process, thank you!
Our vet found a lump and an aspirate was done. X-rays, blood and urine came out fine. But the cytology test came out as “probably anal sac carcinoma”. When they say probable what does that mean? He is going to have an ultra sound next week.
Preparing for worst case scenario, what would be your recommended palliative care? Best case scenario?
As always, thank you!
Should a fine needle aspirate be done or should the lump just be removed? My vet believes that fna are not accurate and can spread cancer and that all lumps should be removed with a wide margin. I am concerned about putting my dog under sedation or anesthesia and subjecting her to that kind of invasive procedure for several lumps without knowing what they are. What do you suggest?
Dear Terry,
fine needle aspirates are used very commonly accross the USA and internationally to help diagnose a cancer. They provide useful information and can give definitive diagnosis, but like any test they have limitations as discussed. The opinion that all lumps should be removed with wide excision without testing is rather unusual.
Best
Dr D
Hi
Thanks for the info, it s very helpful. My boxer had a cyst removed from her hind quarter last year. We did not do a biopsy with a needle, the vet just went in and took it out just in case. I did not realize that this could be done. We went to the vet last week after finding another similar feeling lump a few inches from the last spot. She didn’t seem overly concerned about getting it removed asap, but now after reading about this, maybe it would be a good thing to have done in the mean time?Both of these lumps were pea sized and you could put your fingers around it, so not attached. The hair was growing on it too.
The day after we came home from the vets, however, I found another lump on her front shoulder. This one seems to have grown in a week, is pinkish red (kind of bubbly looking) and has little/no hair growing on it. Would this warrant some immediate concern do you think? Do you think a needle biopsy would be beneficial or should we go straight in and take it out?? It doesn’t seem to be attached to anything again and is the size of a pea. But it does look different… so worried 🙁
Thanks
Aoife
I have an almost 10 yr old unspayed Papillon. Just recently a small hard nodule popped up on one of her lower mammary glands. The first doctor said she had cancer and to have it removed and have her spayed at the same time. I had planned to breed her just for a couple of puppies to keep but could only find a purebred male Pap with an underbite in my price range. So I didn’t want to do that and just didn’t spay her. This nodule is tiny, hard to the touch and is not attached to anything that I can feel. It is tender to the touch but that is it. She still plays, she still throws things at us, she still mumbles, eats, drinks and behaves just like she did before finding this nodule. I had thought of bringing her in for a FNA to see what it is, because I really didn’t want surgery because once open to the air, things spread around fairly quickly or she could wind up dead on the table from anesthesia. My friend contacted her good friend who is a Vet in Germany. He says that once a nodule shows up, it is generally cancer and has already spread. I have very little money and am trying to raise some to help me help my girl, but do not want to do anything that would shorten her life. I do not believe in chemo for myself (I am a nurse) as I don’t believe in poisoning everything to get at the main cause. So I doubt that chemo would be in her future. What do you think about this ‘hard nodule’ near the nipple area?
Thanks for any info.
Dear Barbara,
I would get this addressed. About half of these are cancerous, and it is not actually true that once you find a lump it must have already spread. This is only true some of the time. I’ve got to say my opinion is that of your vet in the US…at least get it biopsied at the minimum so you know what you are dealing with.
Best
Dr D
Dear Dr. Dressler,
My dog has a history of mast cell tumors. She has a bump on her back that I had a FNA done to see what it is. It looked really ugly after the aspiration was done. Also, it seemed swollen in the tissue around it. It really upset me. Is there any risk of the FNA spreading the cancer if it is a mast cell tumor? Thanks, Tracie
I have 1 year/10 months rotty mix Doberman mix hunter. He had a lump on his ear when I got him but the vet to ld me it wa nothing serious but on Xmas day it turned into a scab and we took him to the vet and they put him on antibiotic and we got some test done yesterday and they told us it is mast tumour and they have to remove his ear to do further test?? Is this the only way??? What is there any other test they can do to find out if it is malign or benign without removing his ear?? We treat like our son and we need abut more info,,, how long will be his life spent if we do the op?????
Dear Dr. Dressler,
My dog Rex, a mini bull terrier, has just had a fine-needle aspirate done on a lump that developed on his hind leg, the day before yesterday.
We are waiting for the results…which have not come back to us, yet.
He had licked his tumor in days prior to our visit to the vet, and he developed hives on that leg.
Doesn’t this mean that it will most likely by a mast cell tumor? (I can’t find anything on histiocytomas releasing histamines).
My concern is that during the aspirate, the vet did not draw fluid out with the syringe plunger – but rather just used ONLY the needle top…and I am worried about the potential inconclusive results from the pathologist.
PS. I will add that 2 weeks ago we took Rex into the vet to check out this bump, and they (without a fine-needle aspirate), thought it was benign. It didn’t look like much back then – but it continued to grow and get “raw” and then the hives appeared.
I have a 12 yr old Yorkshire Terrior called Tia. She had two lumps removed 5 yrs ago which due to funds we did not have tested. I took her to the vet on Christmas Eve with an ongoing skin condition and they found another lump in the mammory areaa. Following that she had a FNA 1 week ago on a lump right next to her teet. .The results came back today and were not definitive. The only positive thing I got from it is it’s not a carcinoma. Previous to this Tia had a blood test to test her organ funtion which came back as good. My vet said they could also bring her in early and put her on fluids for a couple of hours before the op and after which would move the drugs out of her system quicker. This is the labs interpretation of the results:
INTERPRETATION – Mixed cell population: population of epithelial cells (cells forming the epithelium. epithelial tissue, epithelium – membranous tissue covering internal organs) consisted with hyperplasia (increased cell production in normal tissue) or more likely neoplasia (The formation or presence of a new, abnormal growth of tissue).
– some spindle cell. (Spindle cells have a unique appearance and are found only in cancerous tumors) proliferation(rapid reproduction of a cell), reactive (showing a response) or neoplastic (an abnormal new growth of tissue).
– mixed inflammation with increased numbers of large lymphocytes (white blood cells) which may indicate involvement of the lymph node in this region. See comment.
COMMENT – the epithelial (cells forming membranous tissue covering internal organs) cells appeared to predominate here and thus this may be an epithelial lesion. Given the region of the mass then mammary tissue is most likely to be involved and this could be a hyperplastic (An abnormal increase in the number of cells in an organ or a tissue with consequent enlargement). lesion but more likely epithelial lesion (an abnormal new growth of tissue). The presence of spindle cells could be reactive or could this could be a mixed neoplasm (an abnormal new growth of tissue).. The significance of the lymphocytes lymphoid cells (white blood cells) is not clear but given that multiple masses are present then involvement of the lymph node in this region may also be possible. In any case excision biopsy of the mass(s) is advised and submission for histology for further diagnosis. Histology will also give information on the degree of tissue invasion which cannot be assessed by cytology.
It seems very contradictory and I am left unsure of my next step, please could you offer your thoughts
Dr D, could you please answer the question above from Ellie February 12, 2011 at 9:56 pm . I think it is very important because I too have heard that needle biopsies as well as open biopsies can spread the cancer cells into the lymph node system and other causing rapid decline and death of an animal, including humans. I had a large breed dog, not that it matters I am sure, who had a lump under one of his legs, the vet felt it was probably just a fatty tumor and that we could leave it alone and just keep an eye on it. Several months later the tumor appeared to triple in size. The vet decided to remove the tumor. One in noticed it did not look so much like a fatty tumor near the bottom side toward the bone and wanted to send it off to pathology.
The results were returned as cancer. The lab also said they did not get a clear margin and suggest further removal until a clean margin could be obtained. The vet said that because she uses a laser in her surgeries it is common for the tissues to shrink and “sear” somewhat, which often does not allow for a clean margin according to the labs scale. The vet felt that she cut almost to the bone when removing this tumor, but would be happy to go back in and see how much more tissue could be removed. Since the dog was 10 yrs old and had just went through the surgery, and she felt comfortable that she got all tissue that looked abnormal and enough to give a clean margin, we opted to wait. Within 10 months the dog became very ill, and anemic. I took him back to the vet, they hydrated him, took blood work, did stomach x-rays and said there was something there but they could not tell what it was. Since he appeared better, gums were white upon arrival, but pink color returned, and he regained energy (wanting to leave), the vet said I could take him home keep an eye on him and bring him back if he appeared worse, other wise they wanted to re-check him in about 10 days. He never made it. He became so ill. He would not eat or drink, was weak, and couldn’t move. I immediately took him into the Emergency Vet, some 30 miles from home, and upon examination they found his stomach to be very swollen, suspected bleeding and aspirated the stomach. They found it full of blood, said he was bleeding profusely into his abdomen and told me he was dying. They felt horrible that there was nothing they could do and recommended we euthanize him to relieve him of his pain, which we did. Having discussed the possibility of cancer cells spreading through needle aspirations tissue biopsy or tumor removal even, the vet acknowledge that this can happen. I would like your opinion and I think that Ellie would as well. I know that finding out of a growth is cancer or not on a young animal would be prudent so that they may live a fuller life, but at what age do you feel the findings, surgeries and treatments would not do much good and could be harder on the animal as well as hasten their death?
I have a 10 year old female now whom they suspect has Melanoma and feel that it has probably spread has she has other growths and lumps, both soft and firm through out her body. One vet suggest surgery, pathology and even chemo, the other said due to age, it is better left alone and just treat for pain should it begin. She eats and drinks well, still wants to play, but I have noticed she has started panting a lot at times, similar to a dog in labor, which I am afraid could indicate pain. It is not too hot in the home, she is not as heavy as the other dog, her brother who is her litter mate, and he does not pant like that. I really need to know if you agree that the biopsies of any time can indeed spread the cancer cells to other parts of the body and hasten the spread of cancer, be it human or animals.
Dear Bobbie
yes at times this is true but only under certain circumstances:
sample collection penetrates a hollow fluid filled tumor that seeds the body cavity from the leak or incision (of course the tumor must be within the chest, abdomen, or an internal organ like the bladder)
OR
the meds used potentiate tumor spread
(high anesthetic doses of ketamine, or barbituates given IV)
Otherwise, no, I do not believe there are many cases that increase metastatic rates…
I hope this helps
Dr D
I have since read that a dogs age should not be the only reason to discount an op. I also read that anaesthetic’s are much safer than they use to be especially in an older dog that has had the blood test and got a good result.
MY RESCUE DOG TARA, HAD A MELANOMA ON HER INSIDE HIP. iT HARDLY GREW AND NOW SHE HAS TWO HARD LUMPS ON HER CHEST, 1 ON HER ARM AND 1 IN HER SHOLDER. THEN I FOUND A HARD LUMP NEAR HER STOMACH. IT IS ABOUT 3 FINGERS WIDE. MY VET, THAT I TRUST WANTS TO REMOVE IT SAYING IT COULD IMPACT HER STOMACH CAVIATY. SHE WANTS TO REMOVE THE TWO OTHER ONES ON HER CHEST AT THE SAME TIME AND CLEAN HER TEETH. WE ARE UNABLE TO SCHEDULE IT UNTIL NOVEMBER 22 DUE TO HER BUSY SURGERY SCHEDULE. TARA IS AT LEAST 12. SHE IS MORE THAN LIKELY PART ROTT, PART DOBERMAN AND POSSIBLY CHOW. SHE IS EATING GOOD AND HAVING NO STOMACH ISSUES WITH BOWL MOVEMENT OR SICK ON HER STOMACH. SHE SEEMS TO TIRE EASY HOWEVER BUT ALERT AND IS CAUSIOUS WHEN PLAYING WITH HER ROTT LITTLE BROTHER. DO YOU THINK I SHOULD PROCEED WITH THE REMOVAL? I AM AFRAID IF IT IS CANCER IT WILL ONLY MAKE IT SPREAD AND I MAY HAVE LESS TIME THAN IF I WERE TO LEAVE IT ALONE. THANK YOU FOR YOUR ADVISE!!
Dear Lyn
please get the lumps tested to see if they are cancerous and if so what type. This will impact what is done;
Best
D
Hi, I have an 11 yr old purebred Lab that we adopted 5 months ago. She has lumps all over her and we had a biopsy done on a lump that is hard around her throat. I have 3 dogs and 3 cats. For some reason I really connected with her. Her name is Sammie and she does not let me out of her sight. Since I had the biopsy, she has been a bit differnet. I am sure she knows what is going on, these animals are way smarter than people could imagine. I asked the Vet how long is the life span, he said about 11 or 12 yrs. Is this true? Do I have anything to worry about the lump or anything spreading from the biopsy? He had to jab the needle a few times because he could not get through.
I have been reading about lymphoma in dogs and aspirations etc. I took my 13 year old dog to a vet and he told me the needle aspiration was inconclusive but he just knew it was cancer. My dog was perfectly healthy on one day, sick two days letter, the next day he was a little better, but after the vet, he started going down hill. I’m taking him to the country vet tomorrow because the more info I’ve been reading from your website, the more I’m sure the vet (he was also not very nice) that we first saw is wrong. My dog was eating, drinking, playing etc, started feeling a bit down (still eating) and now he has “CANCER?””” I will find out tomorrow. Let’s home that guy was wrong.
Dear Brenda,
I hope you are right. Keep us posted, okay?
Best
D
My dog had very enlarged spleen removed 4 months ago – diagnosis high grade
lymphoma – commenced chemo few days later – vinicristin, endoxana, prednisolone. chemo weekly x 8 then every 2 weeks. Prednisolone stopped at
7th week as she contracted ? pancreatitis/stomach problems.
She is an eight year old lab, previous mast cell tumour on ear 3 years ago –
one thirs of ear removed. otherwise, has been healthy. She has now shown
some enlarged lymph nodes. First needle aspiration inconclusive, Second
confirmed lymphoma spread. Vet suggesting changing chemo to doxyrubin.
Finding it hard deciding whats best – concerned re the toxicity to tissue during
administration and potential effects on heart. otherwise, want to give her best chance please help, Terri, uk
Dear Terri,
might discuss DTIC and CCNU, especially for T-cell lymphomas with your vet, and don’t forget to have an oncologist supervise the chemo if possible…
Also don’t forget the other supportive steps- diet, immune support, etc discussed in the Guide..
Best
Dr D