No, those kids up there in the photo aren’t suffering from progressed brain tumors. Rather, they are bagelheads: people who modify their body so that it looks like a giant bagel is growing out of their skin.
The look is accomplished through the use of a saline solution drip, which is injected at your local tattoo/piercing shop by a professional piercer. The injection causes massive swelling, which can then be molded and pressed into the shape of your choosing.
Naturally, the Japanese chose the logical shape of a bagel.
