Benign cysts are quite common on both ovaries and kidneys, but given your past history they are almost certainly looking for cancer. This does not mean that it is cancer, though. Cat scans are effectively instantaneous, producing a computer picture within minutes but there will be some delay, normally a forrtnight or less, while the results are interpreted by specialists. sometimes, though, the interpretation can be done quickly too. Depends on your hospital. Lumps in the kidney can be due to a range of things from cysts to kidney stones, atrophic kidney disorders, traumatic injury ... you won't know until you get the test done. It is non-intrusive, painless and quick. Good luck.