Doctor, I'm A Medical Student And I Just Want To

Doctor, i'm a medical student and i just want to know about the sickness that killed my friend. They said it that it was like a leukemia but it was not that. He got some kind of bruise all over his body, but he wasnt even bump into something or even hurt. I wonder if its thalassemia? Or maybe some others..? Thanks before doctor.. :) Have a nice day