A kidney tumor is an abnormal growth within the kidney. The terms “mass,” “lesion” and “tumor” are often used interchangeably. Tumors may be benign (non-cancerous) or malignant (cancerous). The most common kidney lesion is a fluid-filled area called a cyst . Simple cysts are benign, do not turn into cancer and usually require no follow-up or treatment. Solid kidney tumors can be benign, but are cancerous more than 90 percent of the time. 1

Tumor Growth

Kidney cancer can potentially grow into the renal vein and the vena cava. The renal vein is the kidney’s primary draining vein and the vena cava is the vein that takes blood to the heart. The portion of the cancer that extends into these veins is called “tumor thrombus.” Imaging studies, particularly an MRI, can help to determine if tumor thrombus is present.

Tumors must stimulate the growth of new blood vessels to provide the tumor with nutrients and oxygen. This process, known as angiogenesis, is needed for a tumor to continue to grow and spread to other areas of the body. Kidney cancers are considered very angiogenic and are very efficient at travelling through the blood vessels in the body. They do this by secreting a protein called vascular endothelial growth factor, or VEGF. VEGF acts on nearby blood vessels stimulating them to sprout new vessels to supply the tumor. 2

1. “Kidney Cancer”, American Urological Association Foundation; ,

While clinical studies support the effectiveness of the da Vinci® System when used in minimally invasive surgery, individual results may vary. Surgery with the da Vinci Surgical System may not be appropriate for every individual. Always ask your doctor about all treatment options, as well as their risks and benefits.

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