My dog's foot mass cytology report: What does 'no tumor' mean?

I'm so sorry poor Barney had to have surgery! It can be common with mast cell tumors removed from the limbs to not have clean margins because there isn't a lot of tissue to work with in that area. This doesn't necessarily mean the tumor will return but it does increase the chances. If the pathologist noted that no mitosis was seen this means they did not see any cells in the active stage of dividing. With very malignant tumors there will generally be a lot of mitosis or cell division seen. I hope Barney recovers from his surgery well and that this is the only one he needs!

Thanks for using Petco Pet Education Center, formerly Petcoach! Possibilities include mast cell tumor, soft tissue sarcoma, plasmacytoma, carcinoma, something of a benign origin, among many others. It should be something similar or the same as the FNA. Ultimately, the biopsy is what actually provides the definitive diagnosis. Feel free to contact us back once the results are available and we can try to guide you going forward the best we can. Let's keep our fingers crossed that it is something benign. Good luck and have a great day!

This is a mass (tumor), however, a wart is also a tumor. So the fact that something is a tumor does not necessarily mean that it is malignant. It could also be a benign mass. I would actually consult with her oncologist, as he will have seen many different tumors and will likely have an idea what it could be before doing a fine needle aspirate to determine the type, It will also be important to see this in connection with her melanoma and its prognosis, to determine whether this mass can be left alone due to the life expectancy of your dog, or to see whether this may be a metastasis or unrelated. Unfortunately this mass is in a tricky spot, so removal will be easy, but closing the skin defect will be hard as there is not so much skin available. This is why it is important to have it examined before it gets too big and the skin cannot be closed anymore due to having to remove too much skin with the mass. Please let me know if you have any other questions or concerns and I would be more than happy to help you further. Please take the time to mark this question as helpful or not as it helps us to improve on the quality of our answers to other pet owners. Thank you kindly!

It does look like a mass from the photo. A histocytoma is possible but other masses can look identical like a plasmacytoma or a Mast Cell tumor. A foreign body stuck in the skin can also look like this. I recommend to have Leo checked out. Because Mast Cell tumors are cancerous, it’s best to know for sure what that is on Leo’s foot. The veterinarian may aspirate the mass he get the diagnosis. I hope this is helpful and please feel free to post any additional questions.

Hi, thanks for using Petco Pet Education Center, formerly Petcoach! It depends on the Vet's experience with reading cytology. Most Vets send out their cytology samples to a specialist who is trained to read them. Mast cell tumors have a classic look and tend to be one of the easier tumors to diagnose. You could ask your Vet to send the slides out since that only takes 1-2 days to get them back but sometimes aspirates do not get you an answer. I know you have surgery set up and a biopsy planned. That is the best thing for Precious, to get the mass off and know what it is. It has a high chance of being benign. It is a good thing it hasn't grown much. I wish you the best!

Thank you for submitting your question regarding Max. I recommend that he sees his veterinarian for a procedure known as a fine needle aspirate. The veterinarian will collect a sample of cells and evaluate them under the microscope to diagnose the mass. A histiocytoma is a common benign growth on the extremities of young dogs. Unfortunately, a mast cell tumor is an aggressive cancerous growth that has the same outward appearance. This is why the cells need to be examined. I hope this information helps!

Hello, and thanks for using Petco Pet Education Center, formerly Petcoach. A needle aspirate is the standard way to get an initial "suspected" diagnosis on a lump, but there are limitations to what a needle sample can tell us. If the cells in the needle sample appear worrisome, then the next diagnostic step is to send in a biopsy (surgical "chunk") of the tumor, or to remove the tumor itself and send the whole thing in to the lab for analysis. So, was removal of the ear necessary? I can't say, I don't know enough about the location or size of the mass. I didn't see the slide from the initial needle aspirate. But if the needle aspirate looked worrisome, and the next step is to remove the tumor or cut a piece of the tumor off, then removing that piece of the ear may have been the only way to find out for sure what the tumor was, and whether surgical removal was curative. Rather than regretting in hindsight that the surgery was done because the histopathology report came back as a histiocytoma, I would be focusing on the good news that Tate doesn't have a malignant mast cell tumor. And removal and lab analysis of the tumor was the only way you could have gotten that news. Hope this helps!