Nevus sebaceus or sebaceous nevus (the first term is its Latin name, the second term is its name in English; also known as an "organoid nevus" and "nevus sebaceus of Jadassohn") is a congenital, hairless plaque that typically occurs on the face or scalp. Such nevi are classified as epidermal nevi and can be present at birth, or early childhood, and affect males and females of all races equally. [Source: Wikipedia 
]
