What could a kidney spot be?

A kidney spot could indicate cancer, blood vessel blockage, scarring, an abscess or a cyst, according to WebMD. A kidney spot is an area of the kidney where the radioactive tracer used in kidney scans shows up in high amounts, or not at all.

A hot kidney spot indicates an area where the radioactive tracer collects in a higher amount, possibly due to a tumor containing an abnormally high number of blood vessels, reports WebMD. A cold kidney spot indicates an area where the radioactive tracer does not appear, possibly as a result of scarring, blood vessel blockage, a cyst or an abscess.