Cystic necrosis

Cystic necrosis is mainly caused by renal cancer. The appearance of the tumor is an irregular round or oval mass with a layer of fibrous encapsulation. The blood supply is abundant, the blood vessels are swollen, and there are hyperemia and bleeding areas. The color of the tumor is related to the number of blood vessels, the lipid content in the cancer cells, and bleeding and necrosis. Generally speaking, the active growth area is white, the transparent cells are yellow, and the granule cells or undifferentiated cells are gray. The dark red or red areas are old or fresh bleeding areas, respectively, often with cystic changes, central necrosis, hematomas, or irregular calcifications.