The kidneys are two bean-shaped organs located in the upper-back wall of the abdominal cavity; each weighs about 4 to 5 ounces.
These organs are constantly filtering our blood and producing urine (pee) by removing excess water, salt and waste products. Kidneys also help make red blood cells and control blood pressure.
Kidney cancer occurs when the cells start growing abnormally and don't die off. These abnormal cells often invade other tissues, interfering with the functioning of normal cells. The most common type of cancer is renal cell carcinoma (RCC).
Renal Cell Carcinoma (RCC)
Also known as renal cell cancer or renal cell adenocarcinoma, RCC accounts for about 9 out of 10 kidney cancers.
Renal cell carcinoma usually appears as a single mass (tumor) within a kidney. However, it's possible to have more than one tumor present in a kidney or to have tumors in both kidneys at the same time.
Often, these tumors are found during an imaging test, such as a computed tomography scan (CT) or an ultrasound, performed for concerns unrelated to kidney cancer.
Although some are not noticed until they have become large, most of these cancerous tumors are found before they have spread (metastasized) to other parts of the body.
Different subtypes of renal cell carcinoma are classified according to how the cancer cells look under a microscope. Other types of kidney cancers include transitional cell carcinomas, renal sarcomas and Wilms' tumors.
The following list contains some common symptoms of kidney cancer:
- Blood in your urine (which may make urine look rusty or darker red)
- Feeling very tired
- Weight loss for no known reason
- Pain in your side that doesn't go away
- A lump or mass in your side or abdomen
Overall, the lifetime risk for developing kidney cancer is about 1 in 63 (1.6 percent). Men have a higher likelihood of developing this cancer than women.