Mesoblastic Nephroma

A 10-day-old infant presented with hematuria. Multiple CT images show a large heterogeneous mass originating from the lower pole of the right kidney (cortical beak sign noted, pink arrow). The mass extends into the right renal pelvis and causes mild hydronephrosis.

Facts

• Synonyms: mesoblastic nephroma, leiomyomatous hamartoma, mesenchymal hamartoma, renal fibroma, Bolande tumor.
• It is the most common solid renal tumor in the newborn.
• This tumor is believed to arise from metanephric blastema or secondary mesenchyme.
• Patients usually presents with a palpable flank mass.
• Prognosis is excellent with nephrectomy and wide resection

Imaging Findings

• Large solid intrarenal mass, which typically involves or extends to the renal sinus.
• Hemorrhage, necrosis or cystic portions are uncommon.

Table: Age Presentation of Renal Tumors in Children

References

1. Donnelly LF. Diagnostic imaging pediatrics. Amirsys. Manitoba. 2005.

2. Lowe LH, Isuani BH, Heller RM, Stein SM, Johnson JE, Navarro OM, Hernanz-Schulman M. Pediatric renal masses: Wilms tumor and beyond. Pediatric renal masses: Wilms tumor and beyond. Radiographics. 2000; 20:1585-603.