So on Sunday, I noticed a strange lump looking structure on my guinea pig's (Curly) lower back. I took him to the vet and he told me it was probably a cyst and that he would take Curly to the back and drain it. A few minutes later he came back and said that he was unable to drain it because it it was filled with more of a solid than a liquid. He looked at the small amount of material he was able to extract under a microscope and said that he didn't see any signs of it being cancerous. He guessed that it that the cyst had become infected. Eventually, he came to the conclusion that I had one of two options: either leave the lump there and monitor it and if I see any enlargement of the lump to come in and have it surgically removed, or remove it now and be done with it. The problem is that the "cyst" is already a good size and if I wait then it could become larger, leading to a much larger incision/surgery to remove it. On the other hand, it doesn't seem to be bothering Curly and with surgery, there's the risk of him not handling the anesthetics well. He was born in November 2010, and the vet says there is no guarantee as to whether the cyst will get bigger or stay the same. Please give advice, I'm not sure which way to go!