Wilms Tumor (Nephroblastoma)

It is the most common malignant (cancerous) kidney tumor of childhood, usually occurring in small children aged 3-4 years.

In most cases, a definite cause cannot be found, but it is known to originate from an error in embryological (in the womb) development. It develops when the stem cells that are supposed to turn into a kidney in the womb grow abnormally to form a tumor instead of becoming a kidney.

The most common first symptom that brings the family to the doctor is a palpable, usually painless, unilateral hard and large mass in the child's abdomen. Sometimes this can be accompanied by blood in the urine, unexplained fever, loss of appetite, and high blood pressure.

Families or physicians must absolutely not handle that mass in the child's abdomen roughly and should not press too hard. Wilms tumor is a thin-membraned mass; excessive pressure can cause the tumor to burst and the cancer cells to spread throughout the abdominal cavity.

Abdominal Ultrasonography performed by a Pediatrician or Pediatric Surgeon is the first step. Computed Tomography (CT) or MRI is taken to see the size of the tumor, the other kidney, and the spread (lung metastasis). In order to prevent the cancer from spreading, a biopsy is usually not done before the procedure (It is examined after it is surgically removed).

Wilms tumor is one of the greatest success stories of modern oncology, and the treatment (cure) rate is over 90%. Depending on the size of the tumor, sometimes Chemotherapy is given first to shrink the tumor, and then the cancerous kidney is completely removed by Pediatric Surgery (Nephrectomy). The remaining healthy kidney is perfectly sufficient for the child to live a normal and long life.