Slate grey nevus (congenital dermal melanocytosis, Mongolian spot) is a benign, flat, congenital birthmark, with wavy borders and an irregular shape. In 1883, it was described and named after Mongolians by Erwin Bälz, a German anthropologist based in Japan, who erroneously believed it to be most prevalent among his Mongolian patients. It normally disappears three to five years after birth and almost always by puberty. The most common color is blue, although they can be blue-gray, blue-black or deep ...
在Wikipedia中阅读更多内容