لاتین: Definition Kidney cancer is cancer that originates in the kidneys. Your kidneys are two bean-shaped organs, each about the size of your fist. They're located behind your abdominal organs, with one kidney on each side of your spine. In adults, the most common type of kidney cancer is renal cell carcinoma. Other less common types of kidney cancer can occur. Transitional cell carcinoma, which affects the ureters, can also begin in the kidneys. Children are more likely to develop a kind o ...