Tumors and Growths - Histiocytoma


Growth on Dog Foot- Histiocytoma

Q: Hi... I noticed a growth on my Border Collie/Brittany Spaniel mix's foot. It looks like (this is gross, but...) a Crunch Berry in Captain Crunch cereal. Its about as big as a pencil eraser and is pink and has kind of a rough surface. It doesn't seem to hurt her to touch it, but she licks it alot and even had it bleeding a little yesterday. I'm taking her to the vet this afternoon, but since I am HUGE worrier, I was hoping for some information beforehand. I've been reading on the internet about histiocytoma and malignant histiocytoma and mast cell tumors. Knowing NOTHING about veterinary medicine, it sounds like a histiocytoma, but what might be some of the other possibilities? Thanks! Leanne

A: Leanne- From your description an histiocytoma seems pretty likely. Deep bacterial infections can sometimes look like red angry lumps and fungal infections sometimes take this form, as well. Other skin tumors are possible such as mast cell tumors and immune mediated diseases sometimes cause odd looking lumps, too.

I hope that your vet was able to give you a definite diagnosis and that this was one of the more benign problems.

Mike Richards, DVM

Histiocytoma - continued

Thanks for the clarification..Madision (my dog) had been to the vet and he drew some cells out of the tumor and diagnosed it as a histiocytoma. Needless to say, I was incredibly relieved that it was not a mast cell tumor or something even more sinister. He removed it last Tuesday and, besides the plastic Elizabethan collar she has to wear, she's doing great! Getting her stitches out tomorrow! I'm sorry I did not notice earlier the note on your web page that we should not expect a response right away (I was going to the vet the afternoon I wrote), since you do this in your spare time. Guess I was sorta panicked and didn't want to wait the 2 or 3 hours until my vet visit. I had this mental picture of a full-time Internet Vet, waiting around all day to electronically assuage the fears of neurotic pet owners like myself. Anyway, you do a GREAT service. Thanks a million. Glad there are people like you out there!

A:I am glad that Madison had a minor problem!

We're trying to figure out a way to do this as a full-time endeavor. We really do think that it would help a lot if pet owners could have access to a current reference source for problems affecting their pets. Just like in human medicine, an involved client can make a big difference in the health care their pet receives.

Mike Richards, DVM

Histocytoma or Button Cell Tumor

Q: My husband took our german shepherd to the vet today (that's as bad a letting a husband take a kid to the doc). He, the dog, has a small lump on his chest about the size of a garbanzo bean. The lump is reddish as though it is irritated--I haven't seen him licking it --actually I don't think he can reach that high up. Well, anyway, my husband said the vet called this a "button tumor" and said it was quite serious. Can you expand?

A: Gail- You probably know this by now, but your husband was probably referring to a histiocytoma which is commonly referred to as a "button cell tumor". These are raised red irritated looking tumors that do sort of resemble a button on the skin. A large percentage of these tumors will resolve on their own if they are left alone for 6 to 8 weeks. If they are still present after that time, we recommend removal of the lump. Some vets recommend earlier removal because it is hard to be sure that these are actually histiocytomas and not another more problematic tumor such as a mast cell tumor. The theory in this case is that you can't tell what the lump is by sight so removing all lumps is best. I still think that waiting a few weeks, as long as the lump isn't spreading or growing, is reasonable. If it goes away, surgery isn't necessary and, if it doesn't, I make a lot wider incision around the tumor than I might if I just removed all lumps. Mike Richards, DVM


Michael Richards, D.V.M. co-owns a small animal general veterinary practice in rural tidewater Virginia. Dr. Richards graduated from Iowa State University's College of Veterinary Medicine in 1979, and has been in private practice ever since. Dr. Richards has been the director of the PetCare Forum...