Over the past years, many studies have been done for children with kidney tumors. Each study done has increased what we know about these tumors and has helped doctors plan treatment for subjects with these tumors. Researchers now know that there are some features of kidney tumors that may help predict how subjects will respond to therapy. These include the exact type of tumor cells (this is found out by looking at the tumor tissue with a microscope), the size of the tumor, and in some cases, certain changes in the genetic information (DNA) in the tumor. Researchers also know that some subjects may need different treatment than others, based on this information about the tumor. It is also important in planning your treatment to know if the tumor is found only in the place where it started growing, or if it has spread to nearby tissues or lymph nodes, or even to places far away in the body, like the lungs or brain. This is done with imaging studies (CT and MRI scans). The overall goal of this study is: To find out information about your tumor to help your study doctor know which is the best treatment for your tumor with the least side effects To study kidney tumors so that we may learn more about them and find out more about how to treat subjects who have these tumors. We hope that as more information is learned, we can continue to improve treatments. To store tumor tissue, normal tissue, samples of blood and urine from subjects with kidney tumors so that researchers can do more studies in the future.