Tumor, Wilms

A malignant tumor of the kidney in young children. It is also known as nephroblastoma. Wilms tumor is the most common kidney cancer in children and one the most important malignancies in childhood. About 450 new cases of Wilms tumor are diagnosed each year in the U.S. Wilms tumor has a characteristic appearance under the microscope. (It is composed of small spindle cells and other types of tissue, including kidney tubules and glomeruli, and muscle and cartilage.) The treatment of Wilms tumor exemplifies the effectiveness of combining surgery, chemotherapy, and radiation in the treatment of children with cancer. The mortality (death) rate from Wilms tumor was over 60% in the 1950s. However, the survival rate (without recurrence) 2 years after diagnosis now exceeds 90%. Risk factors for the recurrence of Wilms tumor — when it recurs, it tends to stay in the locality not far where it started — include an advanced stage of the tumor (particularly if there is involvement of the lymph nodes near the aorta), an unfavorable microscopic appearance of the tumor, and spillage of tumor cells at the time of surgery. The name Wilms is neither plural nor possessive. It is the family name of Max Wilms, a German surgeon (1867-1918) who described the tumor.