Discussion of Nephroblastomatosis
- Nephroblastomatosis consists of diffuse or multifocal involvement of the kidneys with nephrogenic rests.
- Nephrogenic rests are foci of metanephric blastema that persist beyond 36 weeks gestation and have the potential for malignant transformation into Wilm's tumor.
- Nephrogenic rest are found incidentally in 1% of infants.
- Currently believed that nephrogenic rests give rise to approximately 30%–40% of Wilms tumors
- Nephrogenic rests are found in up to 99% of bilateral Wilms tumors.
- Treatment for nephrogenic rests is controversial. Some investigators recommend chemotherapy, whereas others maintain that close serial radiologic evaluation of enlarging masses is sufficient.
 Imaging Findings for Nephroblastomatosis
- At CT, macroscopic nephrogenic rests appear as low-attenuation peripheral nodules with poor enhancement relative to that of adjacent normal renal parenchyma.
- At MR imaging, the nodules demonstrate low-signal-intensity foci on both T1-weighted and T2-weighted images.
- US may demonstrate hypoechoic nodules but is less sensitive than MR imaging and CT.
- Diffuse nephroblastomatosis is usually seen as reniform enlargement with a thick peripheral rind of tissue that may show striated enhancement. At US, the enlarged kidney may have diffusely decreased echogenicity.
- Lymphoma can mimic the appearance of nephroblastomatosis but is unusual in infants and young children.
 See Also
 External Links
 References for Nephroblastomatosis
- Lisa H. Lowe, Bernardo H. Isuani, Richard M. Heller, Sharon M. Stein, Joyce E. Johnson, Oscar M. Navarro, and Marta Hernanz-Schulman. Pediatric Renal Masses: Wilms Tumor and Beyond. RadioGraphics 2000 20: 1585-1603.