Needle Aspiration vs. Removal of bump on cat

[whosnott]

Hello, I was hoping to get some advice on what to do with my cat.  About one month ago, I noticed a bump on her back left hip.  I took her to the vet, and the vet was unsure of what could be causing the bump.  He suggested that we watch the bump for a few weeks to see if it grows larger or gets smaller.  It has not seemed to change at all in almost a month.  My cat shows no other signs or symptoms, eats, sleeps, and plays regularly and everything.  My vet is concerned that the bump has not decreased in size and has advised me that I should get the bump removed.  He thinks that the accuracy of a needle aspiration biopsy is low, and that it would be better to just remove the bump through surgery and then test it.  Do you think this is the right decision?  I am jumping the gun by putting my cat through surgery without knowing what is causing the bump?  Or should I go through with the needle aspiration first in hopes of it being non-cancerous, and thus saving my kitty the stress of having surgery if it is not needed?  Are needle aspiration biospies accurate?

[Aleda M Cheng, D.V.M., C.V.A]

I am very glad it was nothing serious!

[whosnott]

Thank you for your help and through answer.  I did however decide to just get the needle aspiration, and good news!  It came back negative for any cancer cells.  My vet seems to be satisfied with the samples we got, and it looks like my cat is in the clear.  Thank you for your reply.

[Aleda M Cheng, D.V.M., C.V.A]

I have to agree with your vet.  A biopsy is always more accurate than a fine needle aspirate.  A full thickness biopsy with wide margins can also be curative.  The usual result of fine needle aspirates (when I perform them) is: probably a lipoma, for example, but the pathologist always says to be definitive please do a biopsy  (the pathologist will rarely commit themselves with just a fine needle aspirate).   If the bump is small enough it can be removed using a punch biopsy which may only require a local anesthetic with sedation.  Additionally, some lumps are so solid that the do not exfoliate easily.  This means that the needle could not extract any cells to be identified and in this case a biopsy would have to  be performed.