Wilms Tumor in Children

Wilms tumor, medically called nephroblastoma, is the most common type of paediatric kidney tumor, usually seen in children between 2 and 5 years of age. Most of the time, parents discover Wilms tumor unexpectedly, sometimes while helping their child bathe or while changing clothes or after noticing that one side of the abdomen looks fuller than usual.

What makes this condition difficult is that many children with kidney cancer otherwise appear normal in the early stages. There may be no severe pain initially, no major symptoms. Just a swelling that slowly becomes noticeable over time. This is why Wilms tumor in children is often diagnosed later than parents expect.

The reassuring part is that modern paediatric oncology treatment has improved treatment options, and many children recover well when treatment begins early.

At Max Super Speciality Hospital, Patparganj, Delhi, Dr. Satyendra Katewa manages children with complex cancers and blood disorders using specialised paediatric haemato-oncology treatments tailored to each child’s stage, age, and overall condition.

What is Wilms Tumor?

Wilms tumor is a common form of kidney cancer in children. It develops from immature kidney cells that fail to mature normally during early childhood development.

In most children, only one kidney is affected. However, in a smaller percentage of cases, both kidneys may develop tumours.

Parents often worry whether diet, infection, or something they missed caused the tumour. In most cases, Wilms tumor develops because of abnormal kidney cell development during early childhood.

Certain genetic syndromes and birth-related abnormalities may increase the risk, but many children with Wilms tumor have no family history at all.

Why Wilms Tumor is Sometimes Missed Initially

One of the reasons Wilms tumor can be challenging to detect is that the early symptoms may resemble common childhood problems.

Many children are initially treated for:

• constipation
• gas or bloating
• stomach infection
• poor appetite
• worm infestation
• mild abdominal discomfort

Before scans eventually reveal a kidney mass. In several cases, the abdominal swelling is painless. A child may continue playing normally despite the tumour growing internally. This is why an unusual abdominal swelling in a child should never be ignored.

Parents can also read about other concerning cancer symptoms in children in our guide on Early Warning Signs of Childhood Blood Cancer. 

In India, some children are diagnosed only after the abdominal swelling becomes visibly large because early symptoms are often mistaken for digestive problems. 

Symptoms of Wilms Tumor in Children

The symptoms vary depending on the tumour size and whether it has spread beyond the kidney.

Common signs parents may notice include:

• A visible abdominal swelling
• Swelling on one side of the stomach
• Abdominal discomfort
• Fever without a clear infection
• Blood in urine
• Reduced appetite
• Fatigue or unusual tiredness
• Weight loss
• Vomiting
• Constipation
• High blood pressure in children

Some children are diagnosed only after imaging is done for unrelated abdominal complaints.

Conditions Associated with Higher Risk

Children with the following conditions may have a higher chance of developing nephroblastoma:

• WAGR syndrome – A rare genetic condition associated with Wilms tumor, eye abnormalities, genital defects, and developmental delay.
• Beckwith-Wiedemann syndrome – An overgrowth disorder in children that can increase the risk of developing abdominal tumours like Wilms tumor.
• Hemihypertrophy – A condition where one side of the body grows larger than the other.
• Congenital urinary abnormalities – Structural problems in the kidneys or urinary tract present since birth that may increase tumour risk in some children.

Children with these syndromes often require periodic screening ultrasounds during early childhood.

How Wilms Tumor is Diagnosed

When doctors suspect a paediatric kidney tumour, imaging usually becomes the first step.

Investigations may include:

• Ultrasound abdomen
• CT scan of abdomen and pelvis
• MRI in selected cases
• Kidney function tests
• Blood investigations
• Urine examination
• Chest CT scan to check spread to lungs

Unlike many adult cancers, diagnosis in children is often based heavily on imaging appearance and tumour behaviour.

Once confirmed, the tumour is staged carefully before treatment planning begins.

Understanding the Stages of Wilms Tumor

Doctors classify Wilms tumor into different stages based on how far the cancer has spread inside the body. Staging helps the pediatric oncology team determine the most appropriate treatment approach, including whether surgery, chemotherapy, or radiation therapy is needed.

Stage 1

The tumor is limited to one kidney and has not spread outside it. The cancer can usually be completely removed with surgery, and treatment outcomes at this stage are generally very favorable.

Stage 2

The tumor has started extending beyond the kidney into nearby tissues or blood vessels, but it can still be fully removed through surgery. Children at this stage often require chemotherapy after surgery to reduce the risk of recurrence.

Stage 3

Cancer cells remain within the abdomen after surgery, or the tumor has spread to nearby lymph nodes or surrounding tissues. In these cases, treatment usually involves a combination of surgery, chemotherapy, and sometimes radiation therapy.

Stage 4

The cancer has spread beyond the abdomen to distant organs, most commonly the lungs, liver, bones, or brain. Children with Stage 4 Wilms tumor usually require more intensive chemotherapy.

Stage 5

Both kidneys are affected by tumors at the time of diagnosis. The main goal in Stage 5 disease is to treat the cancer effectively while preserving as much healthy kidney tissue as possible to maintain long-term kidney function.

The stage of Wilms tumor plays a major role in determining treatment intensity, overall prognosis, and long-term follow-up planning.

Treatment of Wilms Tumor

Without proper treatment consultation, parents are worried about: whether the kidney will need removal, side effects of chemotherapy and future kidney function and, most importantly, whether the child can return to a normal life.

The good news is that children generally tolerate treatment better than adults, and cure rates for Wilms tumor are among the highest in paediatric cancers when managed properly.

Wilms tumor survival rate – As one of the most curable childhood cancers, Wilms tumor carries an overall 90% survival rate, though individual outcomes depend on the cancer’s stage and cell type.

Treatment may involve surgery, chemotherapy, blood component support, and other advanced paediatric oncology procedures, depending on tumour stage and response.

➡️ Advanced Treatment options

Surgery for Wilms Tumor

Surgery remains one of the most important parts of treatment. In many children, the affected kidney is removed through a procedure called nephrectomy.

However, treatment planning is not identical for every child.

If:

• The tumour is very large,
• involves nearby blood vessels,
• or both kidneys are affected,

Then chemotherapy may be started first to shrink the tumour before surgery. This approach helps improve the surgical safety of kidney tissue whenever possible.

Chemotherapy for Wilms Tumor

Chemotherapy for Wilms tumor is highly effective and forms the backbone of treatment in most children.

The medicines used depend on:

• tumour stage
• tumour histology
• spread to lungs or liver
• response to initial treatment

Children usually require multiple chemotherapy cycles over several months. During treatment, careful supportive care becomes extremely important to prevent infections and anaemia.

In advanced or relapsed childhood cancers, specialised treatments such as Bone Marrow Transplant (BMT) may also become part of long-term cancer management planning.

This is where specialised paediatric oncology teams play a major role.

Why Families Consult Dr. Satyendra Katewa

Dr. Satyendra Katewa is a senior Paediatric Haemato-Oncologist and Bone Marrow Transplant specialist with experience in managing childhood cancers, blood disorders, and complex paediatric oncology cases.

Families across India consult him for:

• specialised paediatric oncology treatment
• difficult or relapsed childhood cancers
• multidisciplinary cancer care planning
• 25+ years of experience in treating childhood blood disorders and paediatric cancers
• advanced supportive care during chemotherapy
• 1000+ Successful BMT cases
• bone marrow transplant expertise

Treatment is provided at Max Super Speciality Hospital, Patparganj, Delhi, with access to dedicated paediatric oncology care facilities.

Concerned About an Unusual Swelling or Kidney Tumor in Your Child?

An abdominal swelling in a child should never be ignored, especially if it continues to increase in size or appears only on one side of the abdomen. While many conditions may appear similar initially, some children are diagnosed with Wilms tumor only after imaging scans reveal a kidney mass.

You can book a consultation if your child has an abnormal ultrasound or a suspected kidney tumor

Consult Dr. Satyendra Katewa for expert management of Wilms tumor in children, chemotherapy planning, supportive care, and advanced paediatric oncology treatment in Delhi.