Question about lump on dog (Another update 12/26) Maybe good ending!

[sourland]

So glad that he has decided to keep her.

 

[AinaWGSD]

I am so sorry to hear about this sweet girl's cancer! If it's any consolation at all, with the fact that it is a mast cell tumor it's actually probably a good thing they didn't do a fine needle aspirate. Mast cells can spread aggressively if the cancerous cells are ruptured, such as with a fine needle aspirate (or even by just squeezing the mass too firmly). If the vet had done an aspirate and sent the sample off to a lab to wait for results it could have actually made the situation worse by allowing the cancer to spread faster. The vet I work for sends lumps out for histopathology, but we generally do a fine needle aspirate first and look at the cells under a microscope to determine if the mass is likely to need removal before we schedule surgery. I can't tell you for sure that ugly looking cells are cancerous, but mast cells are very distinct and any time we see them on the microscope we immediately give the dog a benadryl injection and send them home with instructions for oral benadryl (1mg/pound of dog) until we get the histopath results back, and sometimes for life if it comes back as a mast cell tumor. Benadryl (diphenhydramine) slows the spread of ruptured mast cells and may prevent, or at least slow down, remission.

I'm thankful that your uncle has the courage to take on a sweet older dog with cancer. It sounds like they have a lot to offer each other. Best of luck

 

[Brindlebtch]

If it is just one mast cell tumor and it is removed with clean margins, your girl has a good chance of never having another. I have had single mast cell tumors removed from dogs and they lived long, happy and healthy lives with never a recurrence.

This is a quote from the Washington State Vet School:
Biological behavior of mast cell tumors
Most mast cell tumors are considered locally invasive, and can be difficult to remove completely because of the extent of local spread. The behavior of mast cell tumors reflects their grade (a term used by pathologists and oncologists to describe such things as how-well differentiated a tumor is, how frequently it is dividing, how invasive to adjacent structures, and other criteria). Mast cell tumors have 3 grades, with grade I being the least aggressive and least likely to spread to other organs (metastasize), and grade III being highly aggressive tumors with a high likelihood of metastasis; most grade II tumors tend not to metastasize, although they can do so.

So hopefully your girl's tumor has not spread.