Kidney Tumors

What are kidney tumors?

Kidney tumors happen when cells in the kidneys grow out of control and form a lump (mass). Doctors often don’t know exactly what causes these tumors to start and grow. The kidneys are a pair of organs near the bottom of the rib cage. Kidneys filter blood, removing waste and making pee (urine). The urine passes through a long tube and collects in the bladder.

  • 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 at least 8 years old.

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

    • Renal cell carcinoma (usually affects patients 15 years and older)
    • Clear cell carcinoma (usually seen in children under 4 years)
    • Rhabdoid tumor (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

USNWR BadgeAt Seattle Children’s, we care for many families each year who have a child with a kidney tumor. Many of the children we treat never have cancer again.

Doctors at our Cancer and Blood Disorders Center focus on curing cancer in babies, children, teens and young adults. Seattle Children’s treats more pediatric cancer than any other center in the region.

Please contact the center at 206-987-2106 for more information, a second opinion or to make an appointment.

  • A doctor specially trained in diagnosing and treating cancer in children (pediatric oncologist) will guide your child’s care. Our doctors have treated hundreds of children with kidney tumors with excellent results.

    For more than a decade, U.S. News & World Report has consistently ranked Seattle Children's Cancer Center among the best in the nation.

    Through our partnership in the Seattle Cancer Care Alliance (SCCA), your child will benefit from the work of physician-scientists at Fred Hutch and UW Medicine, as well as at Seattle Children’s. The National Cancer Institute has designated our partnership a comprehensive cancer center.

    Our surgeons are specially trained to care for kids and are board certified in pediatric surgery. We are developing ways to remove tumors that are less invasive than traditional surgery. We have published more results in the medical literature on using minimally invasive surgery than most other children’s hospitals.

  • Children don’t react to illness, injury, pain and medicine in the same way as adults. They need – and deserve – care designed just for them. Our doctors base their treatment plans on years of experience and the newest research on what works best – and most safely – for children.

    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, physical therapy and emotional health. Read more about the supportive care we offer.

    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 an international organization of childhood cancer specialists who work to develop new treatments and reduce late effects of the disease and treatments.

  • 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.

    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.

  • We offer the most advanced treatment options for kidney tumors, including medicine (chemotherapy), surgery, radiation therapy and stem cell transplants.

    Proton therapy may be an option if your child needs radiation therapy. Proton therapy delivers radiation more precisely than X-rays. We offer this treatment at SCCA Proton Therapy, the only proton therapy center in the Northwest.

    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.

    A phase 1 clinical trial at Seattle Children’s is testing CAR T-cell immunotherapy in children and young adults with relapsed or refractory solid tumors. The trial is called STRIvE-01. In this trial, the patient’s own T cells are reprogrammed to recognize and target the protein EGFR, which is expressed by many childhood solid tumors, including kidney tumors.

    As leaders in research groups like the Children’s Oncology Group (COG), Seattle Children’s doctors can offer our patients the very latest options being studied in clinical trials. The knowledge we gain through research improves the care we give all children with cancer.

    Read more about cancer research and clinical trials at Seattle Children’s.

Symptoms of Kidney Tumors

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

  • A lump in the belly
  • Pain in the belly
  • Blood in the urine

Diagnosing Kidney Tumors

To find out if your child has a kidney tumor, your 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

Your doctor may want to take pictures of the inside of your child’s body (imaging studies) to look for tumors or areas where cancer is active.

Imaging studies may include:

  • X-ray
  • Ultrasound
  • CT (computed tomography) scan
  • MRI (magnetic resonance imaging) scan

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 is based on whether:

  • The tumor grew beyond the kidney or burst in the belly
  • Doctors can remove all of the tumor during surgery
  • Cancer cells have spread to other parts of the body
  • Both kidneys have tumors

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 health care team will suggest a treatment plan for your child based on:

  • The tumor size and location
  • How the cancer cells look under a microscope
  • If the cancer cells have genetic changes that are considered high risk
  • Your child’s age
  • Their 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 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.

    Usually, kidney tumors only affect 1 kidney. The surgeon usually removes:

    • The kidney with the tumor
    • The tube from the kidney to the bladder (ureter)
    • The fat around the kidney
    • Lymph nodes near the kidney

    It is important to remove these nodes to find out how far the cancer may have spread. Lymph vessels pick up a fluid called lymph from around the body, filter it through lymph nodes and return it to the bloodstream.

    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.

    Sometimes, they also remove nearby structures like the adrenal gland (which sits on top of the kidney).

    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.

    In very rare cases when both kidneys are affected, a child may need a kidney transplant. Seattle Children’s is 1 of the top 5 kidney transplant centers in the United States.

    Surgery is done at our hospital’s main campus in Seattle.

    Learn more about surgery to treat tumors at Seattle Children’s.

  • Chemotherapy means giving your child medicines that kill cancer cells.

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

    Children with kidney cancer get these medicines through a vein (called intravenous or IV). The medicine spreads around the body through the bloodstream to kill cancer cells. 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 unit  as a day procedure.

    See more about getting chemotherapy at Seattle Children’s.

  • Doctors use radiation to treat:

    • Wilms tumors that are stage 3 or 4
    • Most non-Wilms kidney tumors, which are considered high risk

    Most often, radiation therapy for kidney tumors happens after the first surgery and during the same time period as chemotherapy.

    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 depends on your child’s tumor. Options at Seattle Children’s include X-rays and proton therapy. Unlike X-rays, protons stop once they reach their target. In this way, the tumor gets the intended high dose of radiation and healthy tissue away from the tumor receives even less radiation than with targeted X-ray beams.

    Radiation can harm a young child’s developing nervous system and affect bone growth. Our radiation oncologistDr. Ralph Ermoian, is very experienced 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.

  • 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 the Pediatric Blood and Marrow Transplant Program.

  • 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.

    Through our leadership in research groups like COG , Seattle Children’s patients have access to a range of new treatments being studied. The latest options tested in phase 1 clinical trials may be relevant for patients whose cancer does not respond to treatment or comes back.

    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

    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 follow-up routine will depend on your child’s tumor and their treatments. Most of our patients 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 for a referral.

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

Providers, see how to refer a patient.