Image Description
Microscopic Features: Given the lack of capsule, mesoblastic nephroma directly abuts renal parenchyma and frequently entraps islands of renal parenchyma with developing glomeruli and renal tubules. The tumor may infiltrate into renal sinus or perirenal fat (stage 2). Some cases show islands of hyaline cartilage or extramedullary hematopoiesis. Hemorrhage and necrosis are not common in the classic variant.