Contribution of magnetic resonance imaging to prenatal differential diagnosis of renal tumors: report of two cases and review of the literature.

Enlargement of a kidney on prenatal imaging is usually due to hydronephrosis or cystic renal disease, and much less often results from solid tumors such as mesoblastic nephroma, Wilms' tumor, nephroblastomatosis, renal sarcoma, and angiomyolipoma. All can be diagnosed by ultrasound. Magnetic resonance imaging is useful not only in confirming the presence of a renal mass, but also in the evaluation of the contralateral kidney for subtle abnormalities. We present one case each of Wilms' tumor and mesoblastic nephroma, both detected on antenatal ultrasound and further studied with fetal magnetic resonance imaging. Copyright (c) 2010 S. Karger AG, Basel.