Sandbox: DDx Kidney mass

• 40 yo patients

• Abdominal pain
• Hematuria
• Polycythemia symptoms

• Palpable mass

• Arrangement of monotonous small blue embryonal epithelial cells
• Acinar, tubular, or sheetlike configuration
• Psammoma bodies
• Vimentin, pancytokeratin and cytokeratin-19

• Hyperattenuating heterogeneous mass on CT
• Unenhanced large hypovascular mass
• Frequent foci of hemorrhage and necrosis
• Calcification

Nonmalignant causes

anaplastic sarcoma clear cell sarcoma mesoblastic nephroma metanephric stromal tumor nephroblastomatosis / nephrogenic rests neuroblastoma oncocytoid carcinoma after neuroblastoma ossifying