What is Wilms’ Tumor? Wilms' Tumor is a disease in which cancer cells are found in certain parts of a child's kidney. The kidneys are two organs located just above the waist on either side of the spine. They are part of the urinary system and their main function is to filter blood and produce urine to rid the body of waste. The kidneys also produce substances that help control blood pressure and regulate the formation of red blood cells. Cancer is the result of abnormal cell growth. Other childhood kidney tumors include: Clear cell sarcoma of the kidney Rhabdoid tumor of the kidney Neuroepithelial tumor of the kidney According to the National Institute of Health, Wilms’ tumor is curable in the majority of affected children. Risk Factors Doctors do not currently know what causes Wilms' Tumor, but researchers have identified the following possible risk factors: Family history. A child who has a relative with the same cancer may have an increased risk of developing this disease. Certain genetic birth defects. One or two children out of 10 with Wilms' tumors also have birth defects. If a child has these defects at birth, the doctor will also test the child for Wilms' tumor. It is important to note that most children diagnosed with Wilms' tumor do not have any known gene changes or birth defects. Medical research cannot currently explain why they develop these tumors. Common Symptoms Wilms' tumor can be difficult to find early on. In fact, it is usually a parent who first notices a swelling or hard mass on the child's stomach. For some children, the following symptoms may also appear: Stomach pain Fever Blood in the urine High blood pressure If your child has these symptoms, see his/her doctor right away. Diagnosing Wilms’ Tumor If your child is experiencing any of these symptoms, his/her doctor will perform a physical exam (including checking for lumps in the abdomen), will review his/her medical history, and will probably prescribe various tests to find the cause of the symptoms. Tests may include an ultrasound, CT (or CAT) scan, MRI, chest and bone x-rays, and/or a biopsy. Treatment Options Your child’s doctor will work with you and your child to determine the best plan of treatment. The plan will take into account the type and stage of the cancer, as well as your child’s age and general health. Treatment options may include surgery, chemotherapy and/or radiation therapy. Additional Information on Other Childhood Kidney Tumors Clear Cell Sarcoma of the Kidney Clear cell sarcoma of the kidney is a primary kidney tumor. It is not a type of Wilms’ tumor. This tumor can mestasize (spread) to the lung, bone, brain, and soft tissue. If your child has clear cell sarcoma of the kidney, he or she may be treated with surgery to remove the kidney followed by radiation therapy to the abdomen and lung, followed by chemotherapy. Rhabdoid Tumor of the Kidney Rhabdoid Tumor of the Kidney is a type of cancer that grows and spreads quickly. This cancer is usually found in children under the age of 1, usually discovered at an advanced stage, and symptoms include fever and blood in the urine. This type of cancer tends to spread to the lungs and the brain, and is typically treated by removing the kidney followed by chemotherapy. Neuroepithelial Tumor of the Kidney This is a type of cancer that tends to grow and spread quickly. At diagnosis, these tumors have often spread to the outer layer of the kidney, the veins of the kidney, and to other parts of the body. Your child’s doctor will probably recommend participation in a clinical trial as part of treatment.