Wilms Tumor (Nephroblastoma)

Wilms tumor, or nephroblastoma, arises from embryonic kidney tissue that failed to mature. It is the most common kidney cancer in children and is usually diagnosed between two and five years of age. The tumor grows inside a capsule, which is what makes it both survivable and fragile: while the capsule holds, the disease is contained, and once it is breached cancer cells can spread through the abdominal cavity. Most cases are sporadic, though a minority are associated with congenital anomalies of the genitourinary tract.