Each kidney contains about a million nephrons, within which tiny blood vessels called capillaries are intertwined with minute waste-carrying tubes called tubules. Wastes collected by these filters are passed on to the bladder through tubes called ureters, where they are excreted in the form of urine. There are several forms in which cancer may afflict the kidneys. These cells typically grow into a mass, called a tumor. Single tumors are the norm, although more than one tumor can develop simultaneously within one or both kidneys.
Early diagnosis is critically important.
As with most cancers, the earlier kidney tumors are discovered, the better a patient's chances for being treated successfully. Because RCCs can grow to considerable size before they cause pain or discomfort, most cases are discovered only after the disease has progressed to a dangerous level. While the discovery usually comes as a shock to the patient, incidental discovery can be a blessing in disguise. This is because tumors discovered at this stage often are not too far advanced in their development and will respond well to treatment. Survival rates in such cases are high.