Description

• The most common renal tumor in children; fifth most common pediatric malignancy
• An embryonal renal neoplasm containing blastemal, stromal, or epithelial cell types
• System(s) affected: renal/urologic
• Synonym(s): nephroblastoma

Pediatric Considerations
Occurs predominately in children; rare incidence in late adolescence and adults

Epidemiology

Incidence

• WT represents 6–7% of all childhood cancers and comprises 95% of renal cancers in children <15 years (1).
• 650 cases diagnosed annually; incidence of 8.2 cases per 1 million children (1)
• Median age of diagnosis is 36.5 months (1).

Etiology and Pathophysiology

Genetics

• Tumors display recurrent gene mutations involved in either early renal development or epigenetic regulation (e.g., chromatin modification, transcription regulation, miRNA) (1).
• 1/3 of tumors involve mutations of WT1, CTNNB1, or WTX genes (1).
• Majority occur sporadically; familial inheritance <2% (1)

Risk Factors

More frequent in black children; rare in Asian (1)

General Prevention

Genetic counseling recommended for WT and one major abnormality: overgrowth syndromes, hemihyperplasia, aniridia, mental disability, diffuse mesangial sclerosis; or two minor malformations—inguinal or umbilical hernia, hypospadias, renal abnormalities, ectopic testis (1)

Commonly Associated Conditions

• Overgrowth syndromes: Beckwith-Wiedemann syndrome, isolated hemihyperplasia, Perlman syndrome, Simpson-Golabi-Behmel syndrome, CLOVES syndrome, and Sotos syndrome (1)
• Nonovergrowth syndromes: Denys-Drash and Frasier, WAGR, sporadic, familial WT, Bohring-Opitz syndrome, Bloom syndrome, Li-Fraumeni syndrome, Fanconi anemia, Alagille syndrome, trisomy 18, and genitourinary anomalies (1)