Our kidneys’ main job is to filter our blood. Sometimes we develop masses (growths or tumors) inside our kidneys. Some of these growths are cancerous but many are not. You must have your mass checked out to learn if it is cancerous or not.
There are many different options for treatment. Often there are even more choices if your cancer is found early. Your medical team is there to help you. They can help you learn more about the pros and cons of treatments. Here we share more about kidney cancer and the steps you can take if a mass forms in your body.
Our kidneys serve many purposes, but they mainly do the following:
A tumor, or mass, is an abnormal growth in the body. A kidney mass, or tumor, is an abnormal growth in the kidney. Some kidney masses are benign (not cancerous) and some are malignant (cancerous).
One in four kidney masses is benign. Smaller masses are more likely to be benign. Larger masses are more likely to be cancerous. Some tumors may grow slowly while some can be faster growing – or more aggressive. Aggressive tumors may form, grow and spread very quickly.
Most kidney growths (about 40%) are small, localized masses. Localized means that the tumor has not spread - from where it first started. The main classes of tumors are:

Kidney cancer is one of the top 10 most common cancers in the United States, with more than 76,000 new cases diagnosed each year. More men than women are diagnosed with kidney cancer. Kidney cancer can be seen in anyone but is more common in African Americans, American Indians, and Alaskan Native people. You can get kidney cancer at any age but it is more common in older people (those greater than 75 years old). The earlier kidney cancer is diagnosed—the better your chances of survival.
There is no known cause for developing a kidney mass. But there are a number of things that can increase your risk for kidney tumors such as:
Most kidney masses have no symptoms in the early stages. If there are symptoms, they will most likely be:
Over half of kidney masses are found by chance. Often they are found during generic screening or when you see a doctor about some other problem. If your doctor thinks you may have kidney problems, they might send you to a urologist. A urologist is a doctor who specializes in the urinary system.
There are no routine laboratory tests to find kidney masses. Your health care provider may use many tests to help learn more about your kidneys. Here are some tests and procedures you might expect:
The main goals in treating kidney masses are to cure you of cancer and to protect kidney function where possible. Protecting kidney function is especially important for patients with only one kidney or some other kidney disease.
For some patients, surgery will never be needed. For others, surgery may be the best choice. In some instances, you may be advised to have a biopsy of the tumor to learn more about its potential aggressiveness. Then your doctor may recommend one of four treatment choices. These are: