Hi Melody. If what the found is suspicious, the next steps taken will depend on the size and location of the suspicious mass, as well as your feelings about what was found. I'll give you my experience.
In December, 2013, a routine physical uncovered microscopic traces of blood in my urine. My primary referred me for a CT scan, thinking they would find evidence of kidney stones to explain the blood. Surprise. They found what was then a 1.5cm lesion on my right kidney. After verifying it with an ultrasound and another CT, I was referred to a urologic oncologist at Stanford University. A wonderfully caring man, he explained that for lesions my size, the standard of care was monitoring, as a great many of these lesions turn out to not be cancerous at all. He did recognize, however, that some people can't stand the thought that they may have cancer and so told me that he could get it taken out if that was my desire, but that his recommendation was that he not reduce my kidney function without a good reason. In a fit of maturity, I decided to accept his recommendation. I had scans every six months, alternating between CT and ultrasound. Finally, in April, 2016, an ultrasound determined that the lesion had grown to 1.8cm, so he said it was time to take it out. I had a robotic assisted partial neph in June, 2016. My particular brand of kidney cancer was chromophobe renal cell carcinoma. It's rare, making up only 5% of all kidney cancers. However, the good news is that it rarely spreads, rarely recurs and is extremely slow growing. I've had two sets of scans (I was on a six month rescan regimen) that were clean, so the surgeon moved me to once a year scans.
So, in your case, depending on the size and location, you may go through the same treatment plan as me, or the docs may suggest immediate surgery. Again, there's no one size fits all treatments for kidney cancer. But just know that the advancements made over the past few years in treating kidney cancer are phenomenal. And advancements in scanning technologies mean that most kidney cancers are discovered accidentally, like mine. But they're also discovered when the lesions or tumors are much, much smaller and more easily taken care of.
Best wishes for you and if you need any more information, feel free to yell.