large lump on rabbits neck

Question
I have an eight year old lop ear rabbit.  She has recently--in the last 2-3 weeks developed a large lump on her neck.  It is growing very quickly.  I took her to the vet and they did a needle aspiration.  The results came back that it could be sarcoma (I believe this is the word she used) but that they really wanted to do a biopsy or even better yet remove the lump altogether to make sure.  The vet was really not very optimistic though.  She said that by removing the lump if it is in fact cancer-then the cancer could spread more quickly or she could be fine and given some more time to live.  My question is this--should I go for the biopsy--or have the tumor removed completely or just leave it alone?  If she does have cancer are her chances of living longer better to just leave it alone?  The vet said she seems very healthy--she is eating and drinking just fine and her droppings are normal.  She does however seem to be loosing some weight.  I want to do what is best for her--and I don't want her to suffer any.  She had an ear hemotoma (not sure of spelling)several years ago and was really stressed by the surgery.  I just don't know what is the best thing to do--what is your advice?

Answer
Dear Jennifer,

(Sorry for the delay.  My DSL has been down--they're having problems with Earthlink all over Florida--and only now am I able to access the AllExperts site.  I'm going to have to put myself on "vacation" on this site until they get the problem fixed, so I'm sorry I might not be available for followup questions right away.)

This is a very tough call.  If the lump is, indeed, a sarcoma, it is a very aggressive, fast-growing type of cancer, and removing the lump might not slow things down much.  And your vet is right that any surgery could cause cancer cells to enter her bloodstream and spread to other areas of the body.

The problem is that the vet is not sure that it's a sarcoma.  If it's not, then it might be more treatable.  A needle aspirate isn't really adequate for this type of thing.

If the lump is firmly attached to underlying tissues, then the prognosis is not good.  If it moves freely with the skin, then this would be better, and removal of the lump might be worthwhile because it's more likely the whole thing can be removed.

In a difficult case like this, it might not be a bad idea to get a second opinion from another rabbit vet, and you can find one here:

www.rabbit.org/vets

You don't say where the lump is on the neck, but there are some locations that are more likely to turn out to be abcesses, not cancer.  If the lump is near her jaw, then it's possible this could be a molar root abscess.  If it's in the muscle or connective tissue, sarcoma is more likely.  So a second opinion and a second exam from another vet will give you perhaps a better idea of what you're really facing.

I hope this helps.

Dana