Preschooler with an abdominal mass

MRI of multilocular cystic nephroma
Sagittal US of the left kidney (above) shows a multicystic renal mass involving most of the left kidney. Coronal (lower left) and axial (lower right) T1 MRI with contrast of the abdomen shows the left renal mass to contain multiple thin septations and to have no solid component.

The diagnosis was multilocular cystic nephroma.