aka Wilms tumor
Epidemiology
- Peak incidence: between 2 and 5 years
- Most common malignant neoplasm of the kidney in children
Etiology
Can be associated with loss-of-function mutations of tumor suppressor genes WT1 or WT2 on chromosome 11 (W11ms tumor).
Associated syndromes
- WAGR Syndrome: Wilms tumor, Aniridia (absence of iris), Genitourinary anomalies, Retardation (intellectual disability). Caused by deletion of WT1 gene on chromosome 11p13. c
- Denys-Drash Syndrome: Wilms tumor, early-onset nephrotic syndrome (diffuse mesangial sclerosis), and male pseudohermaphroditism. Caused by a mutation of the WT1 gene.
- Beckwith-Wiedemann Syndrome: Wilms tumor, macroglossia, organomegaly, hemihypertrophy, omphalocele. Caused by dysregulation of imprinted genes on chromosome 11p15.5 (WT2 locus).
Pathophysiology
Clinical features
- Abdominal Mass: Asymptomatic, firm, smooth, non-tender, solitary flank/abdominal mass that does NOT cross the midline.
- Hypertension (25–30%): Caused by renal ischemia secondary to tumor compression → ↑ Renin secretion. c
- Hematuria: Microscopic (most common) or gross hematuria.
- Abdominal pain (30–40%): Secondary to tumor stretching or hemorrhage.
- Constitutional symptoms: Low-grade fever, anorexia, weight loss (less frequent than in neuroblastoma).
Tip
Nephroblastoma should be suspected in a toddler with a non-tender abdominal mass, especially if it is firm, smooth, and associated with hematuria and/or hypertension.
Warning
Careless palpation of a nephroblastoma can result in rupture of the renal capsule and tumor spillage!
Diagnostics
Treatment
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