Preschooler with abdominal pain

CT of cystic Wilms tumor
Axial (left) CT with contrast of the abdomen shows a large cystic mass with septations in the left side of the abdomen. Coronal immediate image (above right) shows a claw sign proving the left kidney is the organ of origin of the mass. Coronal delayed image (below right) shows the mass has a mural nodule superiorly within it.

The diagnosis was cystic Wilms tumor.