SIGNS & SYMPTOMS

Normal kidney cells grow in an orderly fashion but cancer cells divide and grow out of control and can disrupt normal body tissues and function of the organ. When the cancer cells grow, they form a mass which is often called a tumor. Sometimes these cancer cells can spread in the blood and form new tumors elsewhere. These new cancerous deposits are called metastases. Fortunately, most tumors are found before they metastasize or spread.

Renal cell carcinoma (RCC) is the most common type of kidney cancer.

Types of Cancer

There are four main types of renal cell carcinoma:
   clear cell type
   granular cell type
   mixed granular and clear cell type
   spindle cell type

The majority of patients contain clear cell or mixed type. The granules in the mixed type are mitochondrial, which are small oval bodies that provide energy for the cell. Spindle type RCC has a tendency to grow more rapidly and spread more quickly. Other types of kidney tumors include transitional cell carcinoma, which constitute only 5 to 8% of kidney tumors. These cancers arise in the renal pelvis or the "drainage pipes of the kidney." They have the same cell type as is found in bladder cancer. In addition, there are kidney tumors that occur in children called Wilms' tumor which constitute another 5 to 6% of tumors. There are also benign tumors, called oncocytomas or angiomyolipomas, which are not cancer, although these tumors are sometimes treated by nephrectomy.