My kidney cancer was found by accident too, about 4.5 cm and the pathologist would not say what stage, but scaled it 3-4 on the Furman (?), meaning, I believe, very aggressive. Kidney was removed 30 days after finding it. Apparently no "margins" broken (suspect that is good) and all is hopeful, and they do believe it was contained. First MRI follow up is next month and very, very nervous.
Was told by the surgeon at MAYO if it comes back, lungs, liver and bones are the most likely areas. Of course now I'm feeling everything, every little pain, bump, etc. . . . it's a mind game and sometimes I win, other times stupid thoughts dominate. Haven't solved that problem yet.
The best to you