guinea pig with spindle cells

Question
Hi, We have a guinea pig who has two lumps on his underbelly. Our vet biopsied them and said that they're spindle cells-- not necessarily cancerous, but inconclusive/possibly precancerous. We decided to have them surgically removed but we just learned that he has since developed two more lumps (in about 2 weeks since his last checkup). Is this is sign that he probably has cancer that is spreading? We don't want to put him through surgery (possibly multiple surgeries now that there are several lumps) if it's unlikely that he'll survive. Any help you can offer would be appreciated.

Answer
Barbara,

Is there a pathologist report on the first lumps removed?  If so, your veterinarian should be able to tell you if these next lumps are related.  If not, then there is not way to tell if the new masses are new masses or a recurrence or metastasis of the original masses.

I wish I could tell you what the future holds, and what the best thing to do is in his case.  But, unfortunately, there are still too many unknowns.  In some cases, discrete masses can pop up independent of each other, and multiple surgeries are needed.  In some cases the mass is a recurrence of the original mass and another surgery will probably not solve the problem.  It all stems back to what the original masses were.....  Without specific pathological identification, there are no answers. Some masses are locally invasive and cured by surgery.  Some masses will spread and surgery will only postpone the inevitable.

I would talk with your veterinarian and see if he/she has the answers to your question.  If you feel like they have not answered you to the best of their ability then I would seek a second opinion.  Remember, though, sometimes the best answer is "I dont know".  I wish I could tell you how to determine if they are truly a good veterinarian with all the answers or one that is in over their head.  I think it's all a matter of trust.