A 2-year-old child presents with a large abdominal mass that does not cross the midline. CT scan shows a well-encapsulated intrarenal mass. Biopsy reveals blastemal, stromal, and epithelial cell types. Which genetic alteration is characteristically associated with the bilateral form of this tumor?

• A MYCN amplification
• B RB1 gene mutation on chromosome 13q14
• C WT1 gene deletion on chromosome 11p13 ✓
• D t(11;22) translocation

Explanation

This is Wilms tumor (nephroblastoma), the most common renal malignancy in children, with triphasic histology (blastemal, stromal, and epithelial elements) being characteristic. Wilms tumor does not cross the midline (unlike neuroblastoma). The WT1 gene on chromosome 11p13 is the tumor suppressor gene associated with Wilms tumor; germline WT1 mutations are associated with Wilms tumor predisposition syndromes (WAGR, Denys-Drash) and bilateral Wilms tumors. MYCN amplification is associated with neuroblastoma; RB1 with retinoblastoma; t(11;22) with Ewing sarcoma.

Reference: Ghai Essential Pediatrics, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.