Nephroblastoma

Definition: What is Wilms tumor (nephroblastoma)?

Wilms tumor (known medically as “nephroblastoma”) is named after the German doctor Dr. Max Wilms, and it is the most common malignant kidney tumor in children. Especially children younger than 5 years of age are often affected.

While the exact cause of Wilms tumor is still unclear, genetic changes appear to play an important role. It tends to occur in association with other rare syndromes such as WAGR syndrome, Wiedemann-Beckwith syndrome, or neurofibromatosis type 1.

The symptoms of nephroblastoma are at first very unspecific and usually result from the growing tumor size and the displacement of surrounding tissue. Therefore, nephroblastoma is usually only discovered quite late.

What are the causes of a nephroblastoma?

How exactly a nephroblastoma originates is still unclear. It appears that genetic mutations can play an important role, as they lead to impaired development of the urogenital tract. The extent to which these defective genes are inherited is still under research.

Patients with nephroblastoma tend to also suffer more frequently with other syndromes related to anatomical malformations of the urogenital tract. Examples include WAGR syndrome, in which the Wilms tumor appears together with genitourinary deformities, mental retardation and an absent iris around the eye.

Further anatomical abnormalities, like horseshoe kidney or undescended testes, seem to increase the chance of developing a Wilms tumor, but the exact link between these diseases is still unclear.

Which symptoms can occur?

As previously stated, symptoms of nephroblastoma are rather unspecific at first, and in about 10% of affected children there are no initial symptoms.

In most cases, a Wilms tumor becomes noticeable as a palpable mass in the abdomen. Additionally, children often complain of a sense of fullness that is present regardless of their meals. A general feeling of fatigue is also common.

Less common symptoms include fever, abdominal pain, and blood in the urine.

How is a Wilms tumor diagnosed?

The most important method of diagnosing a Wilms tumor is a physical examination. If an unspecific palpable or visible mass is found in a child's abdomen, follow-up tests are essential to rule out the presence of nephroblastoma.

This is when imaging techniques are carried out, such as an ultrasound scan and an MRI or CT scan of the abdomen. A contrast agent is usually given to better visualize the kidney function.

If the diagnosis of a Wilms tumor is confirmed, the patient usually has another CT scan of the chest to rule out any existing lung metastases. In addition, a blood test can be performed to detect signs of tumor disease, such as anemia or coagulation disorders.

What therapy and treatment options are available for  nephroblastoma?

The treatment of nephroblastoma begins in almost all cases and stages with several weeks of chemotherapy. This aims to shrink the tumor and limit the risk of tumor rupture prior to surgery.

After the four- to six-week chemotherapy, surgery follows, during which the entire tumor along with the affected kidney is removed. If both kidneys are affected, a kidney-sparing surgery is performed, in which as much of the tumor as possible is removed, but the healthier of the two kidneys is largely preserved.

Following the surgery, a full histopathological examination of the tumor and the surrounding tissue is done to enable appropriate staging of the residual tissue.

Depending on the staging, another course of chemotherapy or radiotherapy may follow after the operation to destroy the remaining tumor tissue.

Prognosis and course: what are the chances of recovery?

The overall prognosis for the treatment of nephroblastoma is very good, with around 90% of treated children being completely cured.

However, left untreated, nephroblastomas are always fatal. For this reason, a doctor should be consulted as soon as a tumor is suspected to initiate treatment as quickly as possible.

Which doctors and clinics are specialists in Wilms tumors?

A Wilms tumor is generally detected by a pediatrician when a physical examination shows signs that suggest this diagnosis. They can then initiate further examinations and refer the patient for radiological tests.

If the cancer is confirmed, treatment is then provided by specialists in pediatric oncology, which are doctors who specialize in childhood cancer. They mostly perform chemo- and radiotherapy and establish contacts to the pediatric surgeons who can perform surgery on the tumor.

Anyone in need of a doctor would expect the best possible medical care for themselves. Therefore, patients are looking for the most suitable clinic for their needs. Since this is not an objective decision and a respectable doctor would refrain from claiming to be the best, patients must trust the experience of a doctor.

We can help you find an appropriate expert for your condition. All the doctors and clinics listed have undergone extensive review and have been verified by us for their outstanding expertise in the field of Wilms tumor. They are looking forward to and are ready to address your questions and treatment requests.