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Wilms' Tumor Diagnosis

Wilms' tumors may be quite large when they are found. In fact, many Wilms' tumors are larger than the kidney where they developed. However, most Wilms' tumors are found before they spread to other organs.

At MD Anderson's Children's Cancer Hospital, our world-renowned specialists take the time to examine each child closely. Their high level of skill and expertise help them pinpoint Wilms' tumors, which can lead to better chances for successful treatment. They are supported by the very latest in leading-edge diagnostic technology.

Diagnostic Tests

If your child has symptoms that may indicate Wilms' tumor, the doctor will examine your child and ask you questions about your child's health and your family medical history.

One or more of the following tests may be used to find out if your child has Wilms' tumor and if it has spread. These tests also may be used to find out if treatment is working.

Imaging tests, which may include:

  • CT or CAT (computed axial tomography) scans
  • MRI (magnetic resonance imaging) scans
  • PET (positron emission tomography) scans
  • Ultrasound
  • X-ray
  • Bone scan


A biopsy is almost always needed to diagnose Wilms' tumor. Because surgery is required for Wilms' tumor treatment, the biopsy may be done at the same time as the surgery to remove the tumor.

Sometimes, doctors may remove cells to examine before doing surgery. If so, one of these methods may be used:

  • Fine needle aspiration (FNA): A thin needle is inserted into the tumor to remove a small amount of tissue or fluid
  • Core biopsy: Similar to FNA, but a thicker needle is used to remove small cylinder-shaped samples (cores)
  • Surgical biopsy: Tissue is removed during an operation

Blood and urine tests

Getting a Second Opinion at Children’s Cancer Hospital

The experts at Children’s Cancer Hospital are highly specialized in diagnosing complex cancers, including Wilms’ tumor. We welcome the opportunity to provide second opinions for Wilms’ tumor.

Clinical Trials

MD Anderson patients have access to clinical trials
offering promising new treatments that cannot be found anywhere else.

Knowledge Center

Find the latest news and information about Wilms' tumor in our Knowledge Center, including blog posts, articles, videos, news releases and more.