General Considerations

• Most common abdominal malignancy of children
• Both kidneys affected synchronously or metachronously in 5-10%
• Peak incidence at 2.5-3 years
• More common in blacks than whites with an approximately equal gender distribution

Clinical Findings

• Asymptomatic abdominal mass most common
• Abdominal pain
• Hematuria
• Hypertension
• Urinary tract infection
• Varicocele
• Aniridia
• Hemihypertrophy
• Beckwith-Wiedemann Syndrome

Imaging Findings

• Ultrasound is frequently the first study
  • Echogenic mass
• CT is useful in determining extent, lymph nodes and liver metastases
• Tumors tend to be large and may cross midline
• Sharply marginated possibly with compressed normal renal tissue
• May be partially cystic from necrosis
• Curvilinear or punctate calcifications
• Invasion of IVC by tumor
• Hypervascular tumors
• On MRI, tumor tends to have decreased signal on T1 and increased on T2

Differential Diagnosis

• Neuroblastoma
• Polycystic kidney disease
• Rhabdomyosarcoma

Treatment

• Nephrectomy followed by chemotherapy
• Postoperative radiation therapy for stage II and IV lesions

Complications

• Impaired renal function following nephrectomy is rare
• Chemotherapeutic agents may be hepatotoxic
• Scoliosis following radiation therapy

Prognosis

• 85-90% survival
  
  

  

Wilm's Tumor. Conventional radiograph of abdomen shows a large right upper mass displacing
bowel loops into the pelvis and accross the midline (blue arrows). Coronal and sagittal reformatted CT
demonstrate a large, heterogeneous mass arising from the right kidney (white arrows). A small
sliver of functioning right kidney is seen to enhance (yellow arrow).
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