Kidney cancer is cancer that begins in the kidneys. The kidneys are two bean-shaped organs, each about the size of a fist. They are located behind the abdominal organs; there is a kidney on each side of the spine.
In adults, renal cell carcinoma is the most common type of kidney cancer. Other less common types of kidney cancer can also occur. Young children are more likely to develop a type of kidney cancer called “Wilms tumor.”
The incidence of kidney cancer appears to be increasing. One reason for this may be the fact that imaging techniques, such as computed tomography (CT), are being used more frequently. These tests can cause more types of kidney cancer to be discovered accidentally. Kidney cancer is often discovered at an early stage, when the cancer is small and confined to the kidney.