Accepted Answer

I'm sorry to hear about the findings on your cat.

A mass in this area is not unheard of, though more often seen in dogs in my experience. It has a chance of being cancerous of course, but also a good chance it is not, and though being FIV positive did not cause this, it is something for your vet to consider when choosing best method of treatment for this.

You have not mentioned whether she was having problems because of this mass that was found, like trouble defecating, rubbing her back end, etc. In cases where it is uncomfortable for the cat, causes problems, etc, then it is generally surgically removed regardless if cancerous or not, but can be taken off with less tissue taken if so.

Your vet can try to "aspirate" this mass in your appointment tomorrow if it can be reached externally by inserting a needle into it. Then, the cells will be placed on a microscope slide and should be sent to a pathologist at the lab to review what cells are found, thus helping to determine whether it is indeed cancerous. Another option, if not causing problems, is to just have it rechecked in a few weeks and have the vet note the size- cancerous tumors will continue to grow or get harder (or both). If not causing problems, it is an option people choose.

If surgery is needed, FIV is a small concern post-op with recovery but certainly many FIV positive cats undergo anesthesia and surgery for many problems, and not one I would rule out just because of the condition. She should be on fluids throughout surgery to keep her blood pressure strong and her blood circulating well, and (immediate injectable) pre- and (oral) post-op antibiotics are often given to help with the healing. If your cat has not shown symptoms of illness from the FIV at all, there's a good chance she is a carrier and though your vet will consider being extra careful with post-op care (perhaps extra day in hospital), she may be no more of a surgical risk than any other healthy middle aged cat.

A full blood profile will be run to make sure her other organs are doing well and able to adequately metabolize and excrete the anesthetics, and if cancerous cells are seen on the slide, they may want to do chest xrays to make sure this has not metastasized and an ultrasound of the abdomen as well. What you choose to do and not do is always up to you, and removing this mass with just the bloodwork done and declining searching for metastasis or even having the aspirate done is always an option you have as well. However, the ultrasound could also help tell how deep this mass goes and how extensive it is as far as what it is attached to, and may require a boarded surgeon instead of your regular vet if it is indeed extensive, as boarded surgeons are quicker and more experienced at getting good margins around this mass to remove safely and not damage major vessels and tissue.

Hope this helps, and I wish you and your cat the best of luck. Let me know if you have further questions.

Christine

Expert:	ChristineLVT
Pos. Feedback:	100.0 %
Accepts:	805
Answered:	4/19/2008

Certified Veterinary Technician

Licensed veterinary technician (B.S. Mercy College), 10 yrs in animal medicine and training