Sandbox: DDx Kidney mass

• 3-4 yo patients
• Asymptomatic abdominal mass
• May have abdominal pain, fever, nausea/vomiting, hematuria, and hypertension
• Beckwith-Wiedemann syndrome and WAGR syndrome

• Unilateral, smooth, firm, nontender, flank mass
• Does not cross the midline

• WT1 and WT2 genes on chromosome 11
• WTX gene on chromosome X

Nonmalignant causes

anaplastic sarcoma clear cell sarcoma mesoblastic nephroma metanephric stromal tumor nephroblastomatosis / nephrogenic rests neuroblastoma oncocytoid carcinoma after neuroblastoma ossifying tumor renal cell carcinoma rhabdoid tumor translocation carcinoma (children) Wilms tumor of children