Preschooler with left upper quadrant pain

CT of clear cell sarcoma of the kidney
Axial CT with contrast of the abdomen (above) shows a round, heterogenously enhancing, well-defined lesion arising from the medulla of the left kidney that demonstrates a claw sign. There is also a round focus of high density in the center of the mass anteriorly. Coronal CT (below) shows fluid in the left perirenal and pararenal spaces.

The diagnosis was clear cell sarcoma of the kidney with active hemorrhage into the tumor.