Halolike Phenomenon Around a Cafe au Lait Spot Superimposed on a Mongolian Spot

摘要

An 8-month-old Caucasian infant with neurofibromatosis type 1 presented with a congenital plexiform neurofibroma and multiple cafe au lait spots. A pale area surrounded one of the cafe au lait spots located on the left gluteus in the area of dermal melanocytosis. This halolike phenomenon results from the disappearance of the Mongolian spot around the cafe au lait spots, revealing normal pigmented skin. This sign has been described rarely in the literature and the pathogenic mechanism is unclear.