Blood cancer

My grandpa was recently told he might have blood cancer. He has had many kinds of cancer on his face and it had spread to his neck and it moved to his lymph nodes. The doctor told him he got "most" of the infected ones out. He took 42 rounds of radiation after surgery. Now he has no use of his legs and has went to rehab to try to learn how to walk again. They did more tests on him and they told him possible cancer of the blood. I was mainly wondering what kind of cancer of the blood it would be. I know he doesnt want me to know very much so he wont tell me everything to keep me from worrying.

Thanks,
Hopeful4grandpa