Kidney Cancer

Renal Cell Carcinoma (RCC)
Renal cell carcinoma (RCC), also known as renal cell cancer or renal cell adenocarcinoma, is by far the most common type of kidney cancer. About 9 out of 10 kidney cancers are renal cell carcinomas.

Although RCC usually grows as a single tumor within a kidney, sometimes there are two or more tumors in one kidney or even tumors in both kidneys at the same time.

There are several subtypes of RCC, based mainly on how the cancer cells look under a microscope. Knowing the subtype of RCC can be a factor in deciding treatment and can also help your doctor determine if your cancer might be due to an inherited genetic syndrome.

Clear Cell Renal Cell Carcinoma

Clear cell renal cell carcinoma 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 is the second most common subtype: about 1 in 10 RCCs are 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

The chromophobe renal cell carcinoma subtype accounts for about 5% (5 in 100 cases) 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 with a microscope.

Rare Types of Renal Cell Carcinoma:

These subtypes are very rare, each making up less than 1% of RCCs:

• Collecting duct RCC
• Multilocular cystic RCC
• Medullary carcinoma
• Mucinous tubular and spindle cell carcinoma
• Neuroblastoma-associated RCC
• 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

Other types of kidney cancers include transitional cell carcinomas, Wilms tumors and renal sarcomas.

Early kidney cancers do not usually cause any signs or symptoms, but larger ones might. Some possible signs and symptoms of kidney cancer include:

• A mass (lump) on the side or lower back
• Anemia (low red blood cell counts)
• Blood in the urine (hematuria)
• Fatigue (tiredness)
• Fever that is not caused by an infection and that doesn’t go away
• Low back pain on one side (not caused by injury)
• Loss of appetite
• Weight loss not caused by dieting

Several risk factors of kidney cancer include:

• Advanced kidney disease
• Certain medications, like phenacetin and diuretics
• Family history of kidney cancer
• Gender (twice as common in men than in women)
• Genetic and hereditary risk factors
• High blood pressure
• Obesity
• Race (more common in African Americans, American Indians and Alaska Natives)