even more crap from johan

I'm making a post instead of a follow-up comment, to ensure everyone has a decent chance of seeing this.
Popo and i just returned from the Veterinary surgeon's office, where we went to get a CT scan earlier today. Dr. Beardsley thinks that if she goes back in and removes more tissue from the same area (some muscle this time), there's an 80% chance that the fibrosarcoma will stay gone (forever). That's pretty good odds, and the risk is pretty small. So Popo's getting more surgery on Tuesday. There will be more pain and a longer recovery period than last time, due to the removal of some muscle. (Last time, it was mostly just the tumor and some fat, i think.)
So all in all, this is very good news. However, while the rollercoaster is on an upward trend at the moment, i've learned it's easier to be ready for anything. This has gone from tumor to cyst to "probably a malignant tumor", to "maybe not a malignant tumor," before being fairly authoritatively declared by the pathologist to be fibrosarcoma. So while i'm feeling a lot better now, i think it will be some time before i can rest easy.
I really do appreciate the replies.
(Oh, and the CT scan machine was way cool.)

I noticed a large lump on and around Popo's right front shoulder on Saturday, Apr. the 16th.
I took Popo into the Hyde Park Animal Clinic on the 18th, and they said it was a tumor, and scheduled her for their next opening for surgery, which was over 2 weeks away (May 5th). Cancer can grow really quickly, and after talking with anassadeina and HPAC, i took AD up on her kind offer to see if her Vet, Susan Culp, could remove the tumor sooner.

Dr Culp was able to work Popo in for surgery on Friday the 22nd. She is an excellent vet with the best bedside manner and follow-up of any medical professional (DVM or MD) i've ever interacted with. The surgery went well, and after about 4 days, Popo is back to her usual, spitfire self.

However, the pathologist at Texas A&M said the tumor was a fibrosarcoma, which is a kind of cancer with a high rate of re-occurance. Even if the tumor itself is successfully removed, others often come back.

More upsetting is the discovery that fibrosarcoma tumors are often found at vaccination sites, as the case is with Popo. The prevailing theory seems to be that the "adjuvants" added to vaccines contribute to the formation of tumors. Adjuvants are substances that cause the cat's immune system will more strongly respond to the vaccine.

So if you are like me and have a cat you care about, there are some things to carefully consider. First, i am told there are now some adjuvant-free vaccines. They are more expensive, but still not much in the grand scheme of things. (Let's say they are $20 instead of $10. It's a small amount of money to reduce a life-threatening risk. And considering surgery costs many hundreds of dollars, it makes monetary sense, too.)

Second, if you keep your cats indoors, they may not need to be vaccinated as often as recommended or required by law. I'm not telling anyone how often to vaccinate their pets. But it's important to consider the risk that the vaccinations do pose. It's small, but significant. Talk about it with your vet. Chances are that they have seen a Vaccine Associated Sarcoma (VAS), and they should not get all crazy because you don't want to put your cat in unnecessary danger.

Third, if you notice some odd bumps or lumps on your pets, get them examined as soon as possible. Tumors can appear at anytime, even years after a vaccination. The earlier tumors are treated, the better the chances of truly getting rid of them.

There's lots of info about Vaccine Associated Sarcomas out there. This is just one site but it's a good overall page.

Popo's getting a CT scan today, to see how successful the surgery was. I don't really know what i'm going to do if this DVM surgeon suggest more surgery or radiation. It's a very tough decision, and as often seems to be the case with cancer, there's not an obvious or easy answer. It mostly seems to boil down to analyzing the probabilities and trying to factor in a few other issues, like quality of life, and unfortunately, money. I've already spent $1,500 on this one tumor, and haven't even done anything "exotic" like raditation or chemo.