Kidney cancer is a disease that starts in the kidneys. It happens when healthy cells in one or both kidneys grow out of control and form a lump (called a tumor).

Renal cell carcinoma is the most common type of kidney cancer in adults. It most often begins in the lining of tiny tubes in the kidney (called “renal tubules”). The renal tubules clean your blood and make urine. Renal cell cancer often stays within the kidney, but it may spread to other parts of the body, most often the bones, lungs, or brain. There are many different types of renal cell carcinoma and about 9 out of 10 kidney cancers are renal cell carcinomas.

 

Kidney Subtypes:

Clear cell renal cell carcinoma – this is the most common form of renal cell carcinoma. About 7 out of 10 people with RCC have this kind of cancer. When seen under a microscope, the cells that make up clear cell RCC look very pale or clear.
Papillary renal cell carcinoma – this is the second most common subtype – about 1 in 10 RCCs are of this type. These cancers form little finger-like projections (called papillae) in some, if not most, of the tumor. Some doctors call these cancers chromophilic because the cells take in certain dyes and look pink under the microscope.
Chromophobe renal cell carcinoma – this subtype accounts for about 5% (5 cases in 100) of RCCs. The cells of these cancers are also pale, like the clear cells, but are much larger and have certain other features that can be recognized when looked at with a microscope .
Rare types of renal cell carcinoma – these subtypes are very rare, each making up less than 1% of RCCs:
Unclassified renal cell carcinoma – rarely, renal cell cancers are labeled as unclassified because the way they look doesn’t fit into any of the other categories or because there is more than one type of cell present.

Risk Factors:

According to the American Cancer Society, about half of kidney cancers could potentially be prevented with the elimination of excess body weight and tobacco smoking, which are the strong risk factors. Additional risk factors include:
– High Blood Pressure
– Chronic Renal Failure
– occupational Exposure to Certain Chemicals
– Radiation Exposure
– Rare Hereditary Conditions