Infant with an abdominal mass

CT of Wilms tumor
Axial CT without intravenous contrast but with oral contrast of the abdomen (above) shows a large right sided abdominal mass that is calcified. Axial CT with intravenous and oral contrast of the abdomen (below) shows the mass is heterogenous in appearance, does not cross the midline, and the normally enhancing right kidney is demonstrating a claw sign along its posterior aspect.

The diagnosis was Wilms tumor of the right kidney.