Diagnostic Approach for Suspected Wilms Tumor

Initial Investigation

The American College of Radiology recommends abdominal ultrasound as the first-line imaging modality for evaluating abdominal masses and hematuria in children, as it confirms the renal origin of the mass and differentiates it from other abdominal pathology 1, 2, 3, 4, 5
Abdominal ultrasound assesses kidney anatomy, size, and position before any intervention, and evaluates for bilateral involvement and associated anomalies 3, 5

The presence and characteristics of the renal mass should be established using abdominal ultrasound, which also evaluates tumor size and extent, involvement of renal vein or inferior vena cava, and contralateral kidney status 3, 4, 5
Chest CT is essential for staging to evaluate pulmonary findings, and should be performed urgently after ultrasound confirmation of renal mass, as it provides accurate assessment of pulmonary nodules for staging purposes 1, 6

The American College of Radiology advises against proceeding directly to CT without ultrasound confirmation of renal origin, as ultrasound may reveal the mass is not renal, changing the entire diagnostic approach 1, 2
Chest CT must follow urgently after confirmation of renal tumor, as the presence of pulmonary metastases significantly impacts staging and treatment intensity 6