Questions About Cancer? 1-800-4-CANCER

What You Need To Know About™

Kidney Cancer

  • Posted: 01/19/2011

Cancer Cells

Cancer begins in cells, the building blocks that make up tissues. Tissues make up the kidneys and the other organs of the body.

Normal cells grow and divide to form new cells as the body needs them. When normal cells grow old or get damaged, they die, and new cells take their place.

Sometimes, this process goes wrong. New cells form when the body doesn’t need them, and old or damaged cells don’t die as they should. The buildup of extra cells often forms a mass of tissue called a growth or tumor.

Tumors in the kidney can be benign (not cancer) or malignant (cancer). Benign tumors are not as harmful as malignant tumors:

  • Benign tumors (such as cysts):
    • are usually not a threat to life
    • can be treated or removed and usually don’t grow back
    • don’t invade the tissues around them
    • don’t spread to other parts of the body
  • Malignant growths:
    • may be a threat to life
    • usually can be removed but can grow back
    • can invade and damage nearby tissues and organs
    • can spread to other parts of the body

Kidney cancer cells can spread by breaking away from the kidney tumor. They can travel through lymph vessels to nearby lymph nodes. They can also spread through blood vessels to the lungs, bones, or liver. After spreading, kidney cancer cells may attach to other tissues and grow to form new tumors that may damage those tissues. See the Staging section 1 for information about kidney cancer that has spread.



Glossary Terms

benign (beh-NINE)
Not cancerous. Benign tumors may grow larger but do not spread to other parts of the body. Also called nonmalignant.
blood vessel (blud VEH-sel)
A tube through which the blood circulates in the body. Blood vessels include a network of arteries, arterioles, capillaries, venules, and veins.
cell (sel)
The individual unit that makes up the tissues of the body. All living things are made up of one or more cells.
cyst (sist)
A sac or capsule in the body. It may be filled with fluid or other material.
lymph node (limf node)
A rounded mass of lymphatic tissue that is surrounded by a capsule of connective tissue. Lymph nodes filter lymph (lymphatic fluid), and they store lymphocytes (white blood cells). They are located along lymphatic vessels. Also called lymph gland.
lymph vessel (limf ...)
A thin tube that carries lymph (lymphatic fluid) and white blood cells through the lymphatic system. Also called lymphatic vessel.
malignant (muh-LIG-nunt)
Cancerous. Malignant cells can invade and destroy nearby tissue and spread to other parts of the body.
tumor (TOO-mer)
An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Tumors may be benign (not cancer), or malignant (cancer). Also called neoplasm.

Table of Links

1http://www.cancer.gov/cancertopics/wyntk/kidney/page7