Cystic nephroma: a rare benign renal tumor.

We report two boys aged 1 year and 2 years 2 months, respectively, with cystic nephromas. Both presented with a painless abdominal mass. Computed tomography showed a homogeneous, multicystic tumor of the lower pole of the kidney in both cases with thin septa without solid parts. Macroscopically, the surface of the tumor was smooth. Both patients underwent a renal-sparing procedure; histology confirmed the diagnosis of cystic nephroma.