What does tumor necrosis mean?

The tumor cells have been killed and can be indicative of a positive response to chemotherapy or your immune system effectively fighting off the cancer cells. Cancerous tumors can often grow very rapidly and cut off their own blood supply that results in cell death in the tumor. Sometimes almost the entire tumor may die. Tumor necrosis as detected on an MRI often indicates a high grade rapidly growing sarcoma. It is also one of the signs of malignancy on pathological examination (looking at it under a microscope). When portions of sarcomas die they often also hemorrhage and have swelling that can be seen on an MRI.