Nephroblastoma

Wilms tumor (Wilmstumor) is the most common abdominal malignant tumor, and its incidence is the highest among pediatric abdominal tumors. Tumors mainly occur in the first 5 years after birth, especially in 2 to 4 years old. The number of cases on the left and right sides is similar, 3 to 10% are bilateral, or occur simultaneously or successively. There is almost no difference between men and women, but most reports have slightly more men than women. Individual cases occur in adults. Because the embryo develops from the metanephros, and the tumor is composed of components that resemble nephrocytes.