Sandbox: DDx Kidney mass
- 50-60 yo male
- Asymptomatic
- Incidental finding on imaging
- May have hematuria and flank pain
- Palpable flank mass
- Large well demarcated tumors
- Large hetrogenous mass
- Perinephric fat-stranding
- Calcification
- Cells arranged in nests
- Granular eosinophilic cytoplasm
- Nuclei uniform and round with no pleomorphism
- KIT positive
Nonmalignant causes
anaplastic sarcoma clear cell sarcoma mesoblastic nephroma metanephric stromal tumor nephroblastomatosis / nephrogenic rests neuroblastoma oncocytoid carcinoma after neuroblastoma ossifying