Renal Neoplasms: Nephroblastoma (Wilms Tumor)

Nephroblastoma, also known eponymously as Wilms tumor, is the most common malignant renal mass in children and has been noted with increased incidence in a number of predisposition syndromes. In this chapter, we will discuss the role for imaging in diagnosis, staging, and reassessment of disease. Ultrasound is frequently used for initial diagnosis, but computed tomography and magnetic resonance imaging are relied upon for more accurate local staging, with similar performance for each modality. Computed tomography offers the benefit of concurrent abdominopelvic and thoracic imaging for staging, but radiation associated with imaging is of concern, particularly in the pediatric population. Magnetic resonance imaging is a radiation-free imaging modality with excellent soft tissue contrast and resolution, but often requires sedation and is not frequently used for pulmonary assessment. Follow-up assessment can be performed using chest radiography and ultrasound, though some advocate use of computed tomography and magnetic resonance imaging in the first two years post-diagnosis.