Speculation Grows About Kim Jong-un’s Head Bandage
I bet he just had a cyst removed, just like his grandfather Kim Il-sung had removed decades prior:

North Korea’s Kim Jong Un was recently photographed out in public with what appeared to be a large green spot on the back of his head, once again fueling speculation over his health — long a topic of global fascination.
Another image showed him sporting an oblong bandage over the blemish. (…….)
On social media in recent days, some have pondered whether a medical procedure could have left behind a dark mark, while others pointed out that Kim’s grandfather and the founder of North Korea, Kim Il Sung, was also pictured when he was alive with a “tennis ball-sized” growth on the back of his head.
Kim’s grandfather died of a heart attack in 1994, as did Kim’s father, Kim Jong Il, who died in 2011 at age 69.
Seattle Times
You can read more at the link.

