In the bulk of Letos films, he is in someway or another drastically disfigured. For example in In Requiem For A Dream his infected arm is amputated, Panic Room sees him severely burned, in Fight Club he's beaten beyond recognition, in Lord Of War he's riddled with bullets and in American Psycho he has an axe driven into his skull. It appears that Leto is setting some sort of trend for himself, and his upcoming role as Batmans chief nemesis may just be the perfect addition to the list of characters that undergo a mutilation of sorts - especially factoring in a certain 'look' fans are dying to see.
