Hi there. I had the exact experience and was told to get a CT to be sure the cancer had not progressed outside the lining of the colon. Mine was in the cecum, and is a neuroendocrine tumor which is different than "traditional cancer". Anyway, the CT scan showed no metastasis, but I was told by my oncologist in Texas that I needed the colon resection surgery, and he scheduled it. In the meantime, I told him that I want a PET scan and he told me I didn't need it if the CT showed nothing. I insisted on the PET, and it took a week of begging him to order it, but he finally did. The PET scan showed that it had spread into my small intestine, two lymph nodes, liver and heart cavity! My oncologist told me that now surgery was out of the question and I needed to start treatment immediately. I put it off, went to the Mayo Clinic in Phoenix, AZ where the most amazing Dr. Sonbol explained everything to me in detail and ordered an echocardiogram to verify that it is indeed in my heart. If not in my heart, then I can proceed with the colon resection, lymph node removal and liver resection. I will be having the Echocardiogram next week. He has given me hope. I know the neuroendocrine tumors are a lot different than than "traditional cancer" (sorry, I can't think of anything else to call it), but I would encourage you to insist on a PET scan even if your insurance doesn't cover it. That's what I did, and I am so happy I did even though it was not good news. But at least now I can do something about it before it grows into a larger problem. I wish you the best, and please do keep me informed of what you end up doing. Hugs, prayers and positive energy are being sent your way!