Unfortunately, kidney cancer rarely causes visible signs or symptoms in its early stages. In the later stages, the most common sign of both renal cell and transitional cell cancers is blood in the urine (hematuria). Most of the time RCC is now found incidentally, during physical examinations for other problems, by imaging studies such as ultrasound, CAT scan or MRI. You may notice the blood when you urinate, or your doctor may detect blood from a urinalysis, a test that specifically checks the contents of your urine.