Cofty, even with the "best" of Drs, they are only human as we are, and you did the absolutly best thing you can do. You took charge and asked the questions that needed to be asked. In doing so you may have now been able to catch something early enough to eliminate it. Scary as it is, be confident in your ability to know your own body. Close to the surface is a good thing. I will pray they remove all that little bugger and either find it begnin, and/or not find anything else. I agree about the PET scan, it is quite helpful.
I hope I can be as aggressive as you are if something like that ever comes up with my own health. That is the single most impportant thing we can remember when doing to Drs, WE know our body and not to take NO as any answer when we don't feel it is the correct answer. Just keep asking the good questions until a satisfactory answer emerges.
I admore you for that :)