How is kidney cancer diagnosed?
If you have symptoms, your doctor will perform a complete medical history and physical exam. The doctor also may order certain tests that can help in diagnosing and assessing cancer. These tests can include:
- Urine tests: A sample of urine is tested to see if it contains blood. Even very small traces of blood, invisible to the naked eye, can be detected in tests of urine samples.
- Blood tests: These tests are done to count the number of each of the different kinds of blood cells, as well as look at different electrolytes in your body. A blood test can show if there are too few red blood cells (anemia), or if your kidney function is impaired (by looking at the creatinine).
- Computed tomography (CT or CAT) scan: This is a special X-ray that uses a computer to create a series of images, or slices, of the inside of the body. This test is often done with intravenous contrast (dye). Patients with impaired kidney function may not be able to receive the dye.
- Magnetic resonance imaging (MRI): This is a test that produces images of the inside of the body using a large magnet, radio waves, and a computer.
- Ultrasound: This test uses high-frequency sound waves that are transmitted through body tissues to create images that are displayed on a monitor. This test is helpful in detecting tumors, which have a different density than healthy tissues.
- Renal mass biopsy: During this procedure, a thin needle is inserted into the tumor, and a small sample of the tissue is removed (biopsy). The doctor will look at the tissue under a microscope to see if there are any cancer cells. Because biopsies for kidney cancer are not always completely reliable, your physician may or may not recommend this test.
Most cancers are grouped by stage, a description of cancer that aids in planning treatment. The stage of a cancer is based on:
- The location and size of the tumor.
- The extent to which the lymph nodes are affected.
- The degree to which the cancer spread, if at all, to other tissue and organs.
The doctor uses information from various tests including CT, MRI, and biopsy to determine the stage of cancer.