Kidney cyst “mass”

I had a scan for a suspected fatty liver and the ultrasound picked up two cysts on my right kidney. These  I am told had a solid “mass” within, so the chap sent me for an immediate CT to “grade” them?

In your experience can these “mass” be fairly typical and nothing to be concerned over, or should I prepare myself for some possible bad news? I’m told result will be sent to me GP in two to three weeks and as you’d imagine this time will go all but too slow!! Any advice gratefully received.