IS Case 373: Wilms Tumor

Nadia F. Yusaf, MD

2009 URMC Imaging Sciences
Publication Date: 2010-03-02


Patient is a 3-year-old male with palpable mass in the left upper quadrant.


There is a large mass in the left renal fossa, 14.5cm craniocaudal, heterogeneous with speckled calcifications. Thin peripheral enhancement suggesting rim of normal kidney. Tumor extends along the left ureter.


Wilms Tumor


Wilms tumor, a.k.a. nephroblastoma, is the most common abdominal cancer of childhood. It occurs between 1-5 years of age, with peak at 3 years. The presentation is typically an asymptomatic abdominal mass in a normal child. In 5% of cases, the tumor is bilateral. The tumor may extend into the renal vein and IVC. Twenty percent of patients have lung metastases. The tumor tends to appear as a solid ball-like mass but may be heterogeneous due to hemorrhage, necrosis and/ or calcification. These tumors arise from the kidney, unlike neuroblastomas which are seen in the suprarenal area. The intrarenal mass is surrounded by a thin rim of renal tissue, referred to as the "claw sign".


  1. Donnelly LF. Pediatric Imaging: The Fundamentals. Saunders, 2009.

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