Approximately 500 cases are seen every year in the United States. Fortunately, this type of tumor is highly responsive to treatment.
Wilms' tumor is a malignant tumor containing metanephric blastema, stromal and epithelial derivatives. Characteristic is the presence of abortive tubules and glomeruli surrounded by a spindled cell stroma. The stroma may include striated muscle, cartilage, bone, fat tissue, fibrous tissue. The tumor is compressing the normal kidney parenchyma.
The mesenchymal component may include cells showing rhabdomyoid differentiation. The rhabdomyoid component may itself show features of malignancy (rhabdomyosarcomatous Wilms).
Wilms' tumors may be separated into 2 prognostic groups based on pathologic characteristics:
- Favorable - Contains well developed components mentioned above
- Anaplastic - Contains diffuse anaplasia (poorly developed cells)
The symptoms that are typical of Wilm's tumor are an abnormally large abdomen, abdominal pain,fever,nausea and vomiting,blood in the urine and high blood pressure in some cases.
The diagnosis of this tumor requires several tests.
- A physical examination. The doctor will look for possible signs of Wilms' tumor.
- Blood and urine tests. Blood tests can't detect Wilms' tumor, but they can provide your child's doctor with an overall assessment of your child's health.
- Imaging tests. Imaging tests that create pictures of your child's kidneys can help your doctor determine whether your child has a kidney tumor. Imaging tests may include ultrasound, computerized tomography (CT) and magnetic resonance imaging (MRI).
- Surgery. If your child has a kidney tumor, your doctor may recommend removing the tumor or the entire kidney to determine if the tumor is cancerous. The removed tissue is analyzed in a laboratory to determine whether cancer is present and what types of cells are involved. This surgery may also serve as treatment for Wilms' tumor.
Once your child's doctor has diagnosed Wilms' tumor, he or she works to determine the extent (stage) of the cancer. Your child's doctor may recommend a chest X-ray, chest CT scan, chest MRI and bone scan to determine whether the cancer has spread beyond the kidneys.
The growth of the cancer is usually described in Stages. The following are the stages for Wilm's tumor.
- Stage I. The cancer is found only in one kidney, and generally can be completely removed with surgery.
- Stage II. The cancer has spread to the tissues and structures near the affected kidney, such as fat or blood vessels, but it can still be completely removed by surgery.
- Stage III. The cancer has spread beyond the kidney area to nearby lymph nodes or other structures within the abdomen, and it may not be completely removed by surgery.
- Stage IV. The cancer has spread to distant structures, such as the lungs, liver, bones or brain.
- Stage V. Cancer cells are found in both kidneys.
· Standard treatment for Wilms' tumor is surgery and chemotherapy. The stage of the tumor and appearance of the cancer cells under a microscope help determine whether your child also needs radiation therapy. At this point, your doctor may tell you the tumor appears to be either favorable or unfavorable (anaplastic) — the histology of the tissue. Children whose tumors have a favorable histology have better survival rates. However, many children with unfavorable histology also have good outcomes.
· Because this type of cancer is rare, your doctor may recommend that you seek treatment at a children's cancer center that has experience treating this type of cancer.
More information : www.mayoclinic.com,