A 2-year-old boy presents with a painless left flank mass crossing the midline. CT shows a large renal mass with calcifications and a claw sign around normal renal parenchyma. Urinary catecholamines are normal. The most likely diagnosis is:

• A Neuroblastoma
• B Wilms tumor (nephroblastoma) ✓
• C Mesoblastic nephroma
• D Clear cell sarcoma of kidney

Explanation

Wilms tumor typically presents as a painless flank mass in children aged 2 to 5 years. The claw sign indicates the mass is renal in origin. Normal urinary catecholamines exclude neuroblastoma. Calcifications are seen in Wilms tumor in about 15 percent of cases. Mesoblastic nephroma occurs in infancy. Clear cell sarcoma is rare and tends to metastasize to bone. Wilms tumor is the most common renal malignancy of childhood.

Reference: Coran's Pediatric Surgery, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.