On this page
What Are Pediatric Kidney Tumors?
Pediatric kidney tumors are malignant (cancerous) cells that form together in the tissues of one or both kidneys in children. The kidneys are two small, bean-shaped organs located on either side of the spine behind the stomach and intestines.
The kidneys’ jobs are to:
- Create urine that gets passed into the bladder.
- Filter and clean blood from excess water, salt, and other waste.
- Make sure the body is producing enough red blood cells.
Kidney tumors develop from cancerous cells in one or both kidneys. Even though we are all born with two kidneys, we can survive with one well-functioning kidney, and often even with less than one kidney. Because of this, kidney-removal surgery is a successful treatment method for children with kidney cancer.
What are the types of pediatric kidney tumors?
There are several kinds of kidney tumors. The most common type is Wilms tumor:
- Wilms tumor is the most common of all kidney tumors, and one of the most common childhood cancers. Wilms tumors, also known as nephroblastomas, typically form before age 3 and rarely after age 6. Wilms tumors can spread to the brain, bones, liver, lungs, or lymph nodes if not detected early.
Other less common types of pediatric kidney tumors include:
- Clear cell sarcoma — The second most common type of kidney tumor in children. Clear cell sarcoma spreads differently from Wilms tumor and may be found outside the kidney. It also may have a higher relapse rate.
- Ewing sarcoma of the kidney — Previously called neuroepithelial tumors, Ewing sarcomas are generally found in young adults and are known to metastasize (spread) quickly.
- Mesoblastic nephroma — Typically diagnosed in the first three months of life, sometimes even through an in-utero ultrasound. It seems to occur more frequently in males than in females.
- Renal cell carcinoma — A rare kidney tumor in young children, but it is the most common kidney cancer in older teenagers. Renal cell carcinoma may be associated with existing conditions, such as Von Hippel-Lindau disease, tuberous sclerosis, neuroblastoma, and sickle cell disease.
- Rhabdoid tumors of the kidney — Fast-spreading tumors generally found in very young children, typically under the age of 2.
What are the stages of kidney tumors?
The stages of renal tumors are usually determined during surgery with a variety of tests or a biopsy (removal of cancerous tissue to be examined under a microscope).
Here’s what you need to know about Wilms tumor stages:
- Stage one Wilms tumor — Means the tumor was successfully removed during surgery, and the cancer did not spread anywhere else.
- Stage two Wilms tumor — Means the tumor was successfully removed but had microscopic spread to either the part of the kidney that collects urine, or the small blood vessels within the kidney.
- Stage three Wilms tumor — Represents cancer that remains in the body after surgery, either because it was biopsied, it was too close to vital organs, the tumor broke open, or cancer had spread to lymph nodes or other areas in the abdominal cavity.
- Stage four Wilms tumor — Means tumors have spread to vital organs, such as the brain, bones, liver, lungs, or distant lymph nodes.
- Stage five Wilms tumor — Means the cancer was found in both kidneys, and each kidney will get its own staged diagnosis depending on the size and location of the tumors.
How common are pediatric kidney tumors?
Childhood cancer is rare to begin with, and tumors in the kidney represent around 7% of all childhood cancers.
What causes pediatric kidney tumors?
Tumors develop in the body when a group of cells begins growing more quickly than they should. These tumors can be benign (noncancerous) or malignant (cancerous). When a tumor is malignant, it means the cells have mutated or changed at the DNA level, leading to the growth and spread of cancerous cells.
Experts still aren’t quite sure why cancer develops in the body, especially in children. While genetic changes and conditions have been linked to kidney cancers, we still don’t know why cancer happens in this way. Thankfully, we have many methods of successfully treating all kinds of pediatric cancers, including kidney cancer, today.
Certain genetic conditions and environmental factors have been linked to certain types of kidney tumors. However, most kidney tumors are not genetic.
Your child may be more likely to be diagnosed with Wilms tumor if they have:
- Aniridia (absent iris in the eye).
- Beckwith-Wiedemann syndrome.
- Been exposed to toxic chemicals while in utero.
- Denys-Drash syndrome.
- Frasier syndrome.
- Family history of Wilms tumor.
- Hemihyperplasia (one body part is significantly larger than normal).
- Urinary tract issues.
- WAGR syndrome.
Your child’s likelihood of renal cell cancer may increase if they have:
- Hereditary leiomyomatosis.
- Inherited certain gene changes associated with kidney cancer from either parent.
- Renal medullary cancer.
- Tuberous sclerosis.
- Undergone chemotherapy or radiation therapy for a previous childhood cancer.
- Von Hippel-Lindau disease.
If your child’s doctor believes the kidney tumors may be due to a genetic condition, your doctor may order genetic testing. These results can help understand any other diseases your child may be at a higher risk for and create a more personalized treatment plan.
In addition, if your child has a genetic condition that makes kidney cancer more likely, your child’s doctor may order screening tests every three months until they are 8 years old. These tests can include ultrasounds, blood tests, or genetic tests, depending on the type of cancer they are at risk for.Complications of pediatric kidney tumors
If left undiagnosed, cancerous tumors in children can spread to other parts of the body and cause serious illness or death. Even after successful treatment for kidney cancer, Wilms tumors and other types of childhood kidney cancers can recur in the kidney or other areas, such as the abdomen, brain, lungs, or liver.
It is best to talk with your child’s care team right away if you believe they may have any type of kidney tumor.
Back to top
What Are the Signs and Symptoms of Pediatric Kidney Tumors?
Many children do not get screened for kidney tumors until the cancer has matured enough to cause symptoms. Other times, parents find a lump in their child’s abdomen, or it is caught during a routine well-child visit.
Symptoms of kidney tumors include:
- Abdominal pain or swelling.
- Bloody urine.
- Constipation.
- High blood pressure.
- Loss of appetite.
- Lump in the abdomen.
- Unexplained fever.
- Unexplained weight loss.
Wilms tumors can spread into other parts of the body and cause additional symptoms, such as:
- A cough that produces blood.
- Difficulty breathing.
- Severe pain in the abdomen.
When should I see a doctor about my child’s kidney tumor symptoms?
If your child is experiencing any of the above symptoms and you think they may have a type of pediatric kidney tumor, call your pediatrician immediately. They will help you take the next best steps for your child.
Back to top
How Do You Diagnose Pediatric Kidney Tumors?
To diagnose kidney tumors in children, doctors will talk with parents about their child’s health history and symptoms, perform a physical exam, order testing, and use imaging technology to see the tumors better.
Your child’s doctor will talk with you about your child and your family’s medical history, including any kidney cancer in the family. You can expect them to perform a physical examination during which they will check for any symptoms, including a lump or swelling of the abdomen.
Tests to diagnose pediatric kidney tumors
Your child’s doctor may also order certain tests to diagnose kidney cancer, including:
- Biopsy – If the tumor seems unsafe to remove at diagnosis, chemotherapy may be the first form of treatment. In that case, or if the type of tumor is not clear, your child’s doctor may request a biopsy of the tumor. Biopsies can be taken during open or minimally invasive surgery or even with a needle placed through the skin using an ultrasound to guide the biopsy needle. This procedure of removing a small amount of tumor tissues for testing may help diagnose the stage and type of kidney cancer, which helps create a more thorough treatment plan.
- Blood tests – These tests may include a complete blood count (CBC), a blood chemistry study, and a renal function test.
- Imaging tests – Your child’s doctor may order a CT scan, MRI, PET scan, ultrasound exam, or x-ray to get a better look at the tumor(s).
- Urine tests – A urinalysis checks urine function. Renal function tests can also be ordered using a urine sample to check that the kidneys are functioning properly.
Pediatric kidney tumor prognosis
The prognosis of different types of kidney cancer depends on various factors. In general, the prognosis for Wilms tumor is considered excellent.
For Wilms tumors, prognosis depends on:
- Child’s age.
- Genetic or chromosomal changes.
- If this is a new or recurring cancer.
- Stage of cancer.
- Type of kidney tumor.
For renal cell cancer, the variables are mainly:
- If the cancer has spread to the lymph nodes.
- Stage of cancer.
If diagnosed with rhabdoid tumor of the kidney, these factors make the biggest difference:
- Child's age.
- If the cancer has spread to the spinal cord or brain.
- Stage of cancer.
For clear cell sarcoma of the kidney, these factors matter in a prognosis:
- Child's age.
- Stage of cancer.
Many factors affect the recovery rate and treatment options:
- Favorable histology — The histology of a tumor — or the condition of its cells as seen under a microscope — affects the recovery rate. A Wilms Tumor with no anaplasia (cells with weird edges and shapes) has a 90% to 95% chance of full recovery. Additionally, some of the kidney tumors, such as Wilms tumors and renal cell carcinomas, appear to have some genetic connections. Tumors with abnormal chromosomes or genes may be more difficult to treat.
- Size and removal of tumor — Tumors that can be completely resected (removed) through surgical treatment have a higher recovery rate. Chemotherapy may also be used to shrink the tumor for removal or to reach cancerous cells in other parts of the body. Generally, Wilms Tumors are more contained than other kinds of kidney tumors.
- Stage of tumor – As with many cancers, stage 1 and stage 2 tumors are more easily treated. The earlier the tumor is detected, the better the chance for removal and treatment.
- Type of tumor — Certain types of kidney tumors have better recovery rates.
Back to top
How Do You Treat Pediatric Kidney Tumors?
There are six main types of treatment methods for children with kidney cancer. The most common treatment method is surgery.
Surgical treatment of kidney tumors
Nephrectomy or partial nephrectomy
Nephrectomy surgery involves removing the entire affected kidney. A partial nephrectomy removes only the part of the kidney that is involved with the tumor, while saving as much of the normal kidney as possible. If cancer is found in both kidneys, your child may undergo both procedures. During surgery, the tumor is removed, and nearby lymph nodes are also sampled to see if the tumor has spread.
If a tumor is too large, too close to vital organs, or the patient is having trouble breathing, surgery may not be possible. In these cases, a biopsy, followed by chemotherapy to shrink the tumor size, is used before surgery.
How long does it take to recover from kidney surgery?
Recovery after kidney surgery depends on the type of surgery and your child's overall health. Most children need a few weeks to recover at first, but full recovery can take several months. Minimally invasive surgeries usually heal faster than open surgeries, and healthier patients often recover more quickly.
Chemotherapy
Chemotherapy is a method of cancer treatment that uses drugs to stop the growth of cancer cells. Chemotherapy can be taken orally or injected through an IV.
Systemic chemotherapy is a common treatment method for Wilms tumor and other childhood kidney cancers. Sometimes chemotherapy is ordered before surgery to shrink the tumor size. Chemotherapy used before surgery is called neoadjuvant therapy. When chemo is used after nephrectomy to kill off any remaining cancer cells, it is called adjuvant therapy.
In some cases of pediatric kidney cancer, high-dose chemotherapy with stem cell rescue is used to destroy cancer cells. In this treatment method, the child’s own stem cells are removed and stored before high amounts of chemotherapy are administered into their body.
After chemotherapy, the stored stem cells are injected back into the child’s body to help restore healthy blood cells. This treatment method may be used for rhabdoid tumors of the kidney and recurring Wilms tumor.
Radiation
Radiation therapy uses high-energy x-rays to treat tumors with pinpoint accuracy, sparing healthy tissue around the tumors. This treatment method is common for Wilms tumor and other childhood kidney cancers.
Immunotherapy
This treatment method uses the patient’s own immune system to fight cancer cells. This technique can help kill renal cell cancer in children by slowing tumor growth and killing off cancer cells.
Targeted therapy
Targeted therapy involves injecting cancer-killing drugs into the body that are targeted toward a specific type of cancer. These types of treatment methods can help children whose kidney tumors have returned.
Follow-up care after kidney tumor treatment
After treatment, you can expect to return for monitoring tests. The frequency and number of follow-up tests will depend on the success of treatments, the stage of cancer, and your child’s overall health. You can expect imaging tests such as CT scans or MRIs to be ordered to check for cancer recurrence.
After kidney-removal surgery, your child’s care team will go over their medical needs and overall lifestyle habits. The team may recommend a nephrologist, or kidney specialist, to make sure your child feels confident and prepared. Luckily, most children who undergo partial nephrectomy can live full lives with only part of a working, healthy kidney.
Lifestyle habits
Learning and maintaining healthy lifestyle habits is helpful for all kids, but it can make a big difference for children who have had kidney cancer treatment. Taking time to explain to your child how and why to protect their kidneys’ health can go a long way.
Back to top
Why Choose UPMC for Pediatric Kidney Tumor Care?
- At Children’s, every child diagnosed with a kidney tumor is handled with an individualized treatment plan and family-centered care.
- Our pediatric surgical oncologists have trained at some of the country's leading pediatric cancer centers and have extensive experience performing nephrectomies and partial nephrectomies on the smallest patients.
- In addition, cutting-edge research and the latest technology provide our patients with the best possible outcomes.
Back to top
