Renal Cell Carcinoma (RCC) is the most common type of kidney cancer, accounting for approximately 85% of all malignant kidney tumors. In RCC, cancerous (malignant) cells develop in the lining of the kidney tubules and grow into a mass called a tumor. Like many other cancers, the growth begins small and grows larger over time. RCC typically grows as a single mass. However, there are cases where a kidney may contain more than one tumor, or tumors are found in both kidneys at the same time.
Sub-Types of Renal Cell Carcinoma (RCC):
There are five main sub-types of renal cell carcinoma that are identified by examining the tumor under a microscope: clear cell, papillary, chromophobe, collecting duct and "unclassified."
Recent data suggests that clear cell RCC has a slightly worse prognosis as compared to papillary or chromophobe cell RCC. However, the majority of low stage tumors, regardless of cell type, can be cured with surgical resection. Spindle cell types, or sarcomas, tend to grow and spread more quickly than the other kinds of renal cell carcinoma. It can be associated with any of the subtypes mentioned, and this subtype is a sign of a poor prognosis.
RCC accounts for about 90% of malignant kidney tumors. Less common types of cancerous tumors include transitional cell carcinomas, Wilms tumors and renal sarcomas.
Transitional Cell Carcinoma:
About 5% to 10% of all kidney tumors are transitional cell carcinomas, also known as urothelial carcinomas. Transitional cell carcinomas begin in the renal pelvis (the junction of ureter and kidney). Under the microscope, transitional cell carcinomas look like bladder cancer cells and act very much like bladder cancer. Studies have shown that, like bladder cancer, these cancers are linked to cigarette smoking and occupational exposures to certain cancer-causing chemicals.
The signs and symptoms of transitional cell carcinoma are typically the same as with the signs and symptoms of kidney cancer - blood in the urine and, sometimes, back pain.
Transitional cell carcinomas are usually treated by surgically removing the entire kidney and the ureter, as well as the section of the bladder where the ureter is attached. Chemotherapy and radiation therapy are often used in addition to surgery, depending on how much cancer is found. As with RCC, with early stage transitional cell carinomas, there are several treatments. If you have early transitional cell carcinoma, you have several treatment options available. There are different ways to surgically treat early disease. Newer surgical techniques are also being studied. You should talk with your surgeon and be aware of your options and the benefits and risks of those options.
About 90% of transitional cell carcinomas of the kidney are curable if they are found early enough. The chances for cure drop dramatically if the tumor has grown into the ureter wall, or if it has a more aggressive (high-grade) appearance when viewed under the microscope.
Some types of kidney tumors (including renal cell adenomas, renal oncocytomas and angiomyolipomas) do not usually spread (metastasize) to other parts of the body, although they can still grow and cause problems.