by Gloria S. Akande

Created on: November 11, 2009

Childhood Wilms Tumor (WT) or nephroblastoma was first described by Max Wilms, a surgeon in 1899. WT accounts for 6% of all pediatric malignancies and is the most common kidney or renal tumor, representing about 85% of such malignant tumors. Both kidneys may be involved in 5% to 10% of cases. WT has no single gene mutation but the WT1 gene is the target, of mutations and deletions.WT1 it is associated with several syndromes, the WAGR syndrome (aniridia, the lack of an iris, genitourinary abnormalities and retardation) with a 30% risk of developing WT, the Denys-Drash syndrome (pseudohermaphroditism, kidney disease) with 90% risk and the Beckwith-Wiedermann syndrome (facial dysmorphism, hemihypertrophy of enlargement of the half of the body or overgrowth) having a 5% risk of developing WT. Approximately 400 to 500 cases of WT occur per year in the United States and 90% of the tumors are diagnosed by 6 years of age.

The typical presentation of WT is that of an abdominal mass found on clinical examination or noted by the parents. Patients may also complain of abdominal pain, nausea or vomiting, not feeling hungry, or not feeling well. There may be blood in the urine in a third of patients. Patients with later stage disease may present with enlarged liver, abdominal distention with fluid in the belly of ascites and congestive heart failure. This occurs because of extension of the tumor into the renal vein and inferior vena cava . High blood pressure may also occur.

The usual laboratory studies ordered are that of a urinalysis, complete blood count, a chemistry profile for kidney function studies, electrolytes and calcium with coagulation studies. Cytogenetic studies may be ordered if the patient presents with WAGR, BWS or Denys-Drash syndrome. Radiology studies may include a chest X ray, abdominal ultrasound and CT scan to determine the spread of tumor to lymph nodes, major blood vessels, both kidneys and to the liver.

This tumor is treatable and the prognosis is dependent upon the stage of diagnosis and the histopathology of the disease, the patient's age and the tumor size. The histopathology of the tumor may be favorable or unfavorable. These changes have a major prognostic and therapeutic significance. Approximately 5% of tumor have an unfavorable histology where cells have anaplastic nuclear changes where the nuclei of the cells are enlarged and have a higher chromatin content. Anaplasia may be focal or diffuse.

The staging by the Children's Oncology Group

• 1
• 2
• Next Page >>