Kidney Tumors

What are kidney tumors?

Kidney tumors happen when cells in the kidneys grow out of control and form a lump (mass). The kidneys are a pair of organs near the bottom of the rib cage. Kidneys filter blood, removing waste and making pee (urine).

Doctors often do not know exactly what causes these tumors to start and grow. Tumors can be cancerous (malignant) or noncancerous (benign). Kidney tumors are rare in children and teens. When a tumor grows in a child’s kidney, it is likely to be cancerous.

In children younger than 15 years, most kidney cancers are Wilms tumor. Usually it is diagnosed in children younger than 6 years old.

The chance of having Wilms tumor is higher in children with certain genetic syndromes, such as WAGR syndrome, Frasier syndrome or Beckwith-Widemann syndrome. Children at higher risk should be screened regularly using ultrasound until they are 8 to 10 years old. Our Cancer Predisposition Clinic screens and cares for children born with a gene change that raises their cancer risk. 

  • Other types of kidney cancer

    These other types of kidney tumors are very rare but do happen in children and teens:

    • Renal cell carcinoma (mainly affects patients 15 years and older)
    • Clear cell sarcoma of the kidney (most often seen in children under 4 years)
    • Rhabdoid tumor of the kidney (mainly affects children under 4 years)
    • Renal medullary carcinoma (most often seen in African-American children with sickle cell trait and, rarely, in patients with sickle cell disease.)

Kidney Tumors at Seattle Children’s

Our Solid Tumor Program team has cared for many children with kidney tumors. Our experienced experts will diagnose your child and recommend the right treatment.

If you would like an appointment, ask your primary care provider to refer you to our Cancer and Blood Disorders Center.

If you have a referral or would like a second opinion, contact the cancer center at 206-987-2106 or by email.

Providers, see how to refer a patient.

  • The experts you need for comprehensive care

    Our doctors have treated hundreds of children with kidney tumors with excellent results. As needed, your child will get care from doctors who are:

    • Specially trained in diagnosing and treating cancer in children (pediatric oncologists)
    • Board certified in pediatric surgery
    • Experts in using radiation to treat children’s cancer (radiation oncologists)

    We treat more pediatric cancer than any other center in the region. 

    Your child will benefit from the work of physician-scientists at Fred Hutchinson Cancer Center and UW Medicine, as well as at Seattle Children’s. The National Cancer Institute has named our partnership a comprehensive cancer center.

  • Specialists in caring for children

    Our specialty is treating children’s disease while helping them grow up to be healthy and productive adults.

    Our team cares for your whole child. We don’t just treat their disease. As needed, your child will receive care from specialists in nutrition, pain management, pharmacy, palliative care, physical therapy and emotional health.  Read more about the supportive care we offer.

    Children do not react to illness, injury, pain and medicine in the same way as adults. They need — and deserve — care designed just for them. We plan your child’s treatment based on years of experience and the newest research on what works best — and most safely — for children.

    We know that teens and young adults with cancer have different challenges than young children. Our Adolescent and Young Adult Cancer Program works to meet their needs, which may include fertility preservation.

    Our experts focus on how treatments today affect growing bodies in the future. Dr. Eric Chow chairs the Outcomes and Survivorship Committee of the Children’s Oncology Group (COG). The COG is a worldwide group of childhood cancer specialists who work to develop new treatments and reduce late effects of cancer and its treatments.

  • Support for your whole family

    Learning that your child has a kidney tumor can be scary. We help take positive steps right away by offering appointments in 1 to 3 days to children suspected to have cancer. If needs are not urgent, new patients can be seen in 1 to 2 weeks.

    During visits, we take time to explain your child’s condition. We help you fully understand your treatment options and make the choices that are right for your family.

    Our doctors, nurses, child life specialists and social workers help your child and your family through the challenges of their illness. We connect you to community resources and support groups.

    At Seattle Children's, we work with many children and families from around the Northwest and beyond. Whether you live nearby or far away, we can help with financial counseling, schooling, housing, transportation, interpreter services and spiritual care. Read about our services for patients and families.

  • The most advanced therapies and clinical trials

    We offer the most advanced treatments for kidney tumors. Options include medicine (chemotherapy), surgery, radiation therapy and, if needed, immunotherapy and stem cell transplants.

    We provide stem cell transplants through Fred Hutch, whose doctors pioneered this lifesaving treatment. If your child needs a stem cell transplant, their cancer doctor will work closely with the transplant team to plan their treatment.

    As national leaders in cancer research, we can offer our patients the very latest treatments being studied. Depending on your child’s diagnosis, their options may include research studies of new medicines or new combinations of medicines.

    We have one of the nation’s largest pipelines of CAR T-cell immunotherapy trials for children and young adults

Symptoms of Kidney Tumors

These symptoms may be caused by a kidney tumor or by another problem. Check with a doctor if your child has any of these:

  • A mass in the belly
  • Pain in the belly
  • Blood in their pee

Diagnosing Kidney Tumors

To find out if your child has a kidney tumor, the doctor will:

  • Check your child for signs of illness
  • Ask about your child’s health
  • Do tests to look for signs of kidney tumors, such as:
    • Blood tests that look at levels of white and red blood cells and for substances that show how well the kidneys are working
    • Urine tests that look for blood and other substances in your child’s pee
    • Imaging studies to look for tumors or areas where cancer is active. Doctors may take pictures of the inside of your child’s body using X-rays, ultrasound, CT (computed tomography) scans or MRI (magnetic resonance imaging) scans.

Stages of Kidney Tumors

It is important to find out how large a tumor is and how far cancer has spread. This process is called staging. Knowing the stage of your child’s cancer helps your doctor plan the right treatment.

Staging based on these factors:

  • If the tumor has grown beyond the kidney or burst in the belly
  • If doctors can remove all of the tumor during surgery
  • If both kidneys have tumors
  • If cancer cells have spread from the tumor to other parts of the body

Your child’s doctor can tell you about the staging system used for your child’s cancer.

Treating Kidney Tumors

Our goal of treatment is to give your child or teen the best chance of a long and healthy life. Your child's doctor and healthcare team will suggest a treatment plan for your child based on:

  • The tumor size and location
  • Features of the cancer cells under a microscope
  • If the cancer cells have genetic changes that are considered high-risk
  • Your child's age
  • Your child’s overall health
  • Your family’s preferences

The most common treatments for kidney tumors are surgery and chemotherapy. Seattle Children’s offers these treatment options:

Treatment Options

  • Surgery

    Surgery is often the first treatment a child has for a kidney tumor. Our general and thoracic surgery team has performed hundreds of surgeries to remove kidney tumors from children.

    Most often, tumors only affect 1 kidney. The surgeon may remove:

    • The kidney with the tumor
    • The tube from the kidney to the bladder (ureter)
    • The fat around the kidney
    • Lymph nodes near the kidney to find out how far the cancer may have spread

    During surgery, doctors may check other areas for cancer, such as the liver and the other kidney. They may remove all tissue that appears to have cancer.

    In some cases, doctors cannot remove the whole tumor. It may be too large, or the cancer cells may have spread to nearby tissue. Instead, doctors take a small sample of tumor cells for a biopsy to learn more about your child’s tumor. They may recommend chemotherapy to shrink the tumor before removing it.

    Rarely, both kidneys are affected. Very few of these people need a kidney transplant. Seattle Children's Kidney Transplant Program has been named a Center of Excellence by Optum's Clinical Sciences Institute and a Program of Excellence by Cigna LifeSOURCE.

    Learn more about surgery to treat tumors at Seattle Children’s. Surgery is done at our main hospital campus in Seattle.

  • Chemotherapy

    Chemotherapy refers to medicines that kill cancer cells.

    Your child’s doctors may suggest chemotherapy to shrink the kidney tumor and/or to kill cancer cells that might be elsewhere in your child’s body.

    Most children with kidney cancer get these medicines through a vein (called intravenous or IV). The medicine enters the bloodstream and treats cancer cells in the whole body. The type of chemotherapy your child gets depends on the type of tumor.

    Our patients receive chemotherapy at our main hospital campus in Seattle. Most children get chemotherapy at our outpatient infusion center as a day procedure.

    See more about getting chemotherapy at Seattle Children’s.

  • Radiation therapy

    Doctors use radiation as part of treating:

    • Wilms tumors that are stage 3 or 4
    • Some other kidney tumors that are considered high-risk

    Radiation therapy uses high-energy particles to kill cancer cells. A machine sends a dose of radiation into the body. Doctors aim the radiation at the place where they know or suspect there is cancer.

    The best radiation treatment for your child depends on the type of tumor they have.

    Our radiation oncologist, Dr. Ralph Ermoian, is very experienced in caring for children. He helps your child’s team decide if radiation may be helpful and what type of radiation to use.

    Learn more about Seattle Children's Radiation Therapy Service.

  • High-dose chemotherapy and stem cell transplant

    If your child’s tumor comes back after treatment, your doctor may suggest high doses of chemotherapy followed by an infusion of their own blood-forming (hematopoietic) stem cells. This is called a stem cell transplant.

    High-dose chemotherapy may work better to treat some tumors than standard-dose chemotherapy. But the drugs damage the bone marrow’s ability to make new blood cells. That’s why your child needs a transplant of healthy, stored stem cells.

    A stem cell transplant using a child’s own cells is called autologous (aw-TAH-luh-gus). Before high-dose chemotherapy, doctors will remove stem cells from your child. The cells are frozen and stored. After chemotherapy is finished, doctors return the stem cells to your child's body through a vein.

    Our patients who need a stem cell transplant receive this care through Seattle Children's and our partner in the Seattle Cancer Care Alliance, Fred Hutch. Fred Hutch is one of the largest stem cell transplant centers in the world.

    Learn more about our Pediatric Blood and Marrow Transplant Program.

  • Clinical trials, including immunotherapy

    Many children, adolescents and young adults choose to take part in research studies while receiving their standard medical treatment. These studies are called clinical or therapeutic trials.

    Your child’s doctor will talk with you about any treatment options that are available for your child. Then you can decide whether you want to take part in a research study.

    Our researchers are studying:

    • The safe amount of new drugs to give patients.
    • Whether new treatments or techniques work better than current treatments.
    • The genetics of Wilms tumor.
    • Long-term outcomes for children who have had successful treatment.
    • Ways to reprogram the body’s infection-fighting T cells to find and destroy cancer cells. We offer phase 1 clinical trials of CAR T-cell immunotherapy (STRIvE). Immunotherapy may be an option for children and young adults with tumors that are difficult to treat (refractory) or that come back after treatment (relapsed).

    Learn more about cancer clinical trials at Seattle Children’s

Follow-Up Care

Follow-up care is important after treatment ends — no matter what type of treatment your child had. The appointments they will need depend on your child’s tumor and their treatments.

Most people who had cancerous tumors visit Seattle Children’s for follow-up care for 5 years. If you live far from Seattle, your child may get some follow-up care from a cancer doctor in your own community.

Our Cancer Survivor Program provides long-term follow-up care to help young people stay healthy after being treated for cancer in childhood.

During follow-up visits at Seattle Children’s, your child’s team will:

  • Look for any signs that cancer is returning
  • Check for effects that may happen months or years after treatment
  • Tell you and your child about any risk for other cancers and signs to watch for

Contact Us 

If you would like an appointment, ask your child’s primary care provider to refer you.

If you have a referral or would like a second opinion, contact the Cancer and Blood Disorders Center at 206-987-2106 or by email.

Providers, see how to refer a patient.

Paying for Care

Learn about paying for care at Seattle Children’s, including insurance coverage, billing and financial assistance.

For Healthcare Professionals