History: The common blue nevus occurs as a small, well-circumscribed, dome-shaped nodule of slate blue or blue-black color. The lesion rarely exceeds 1 cm in diameter. Common blue nevi are frequently found on or near the dorsa of the hands and feet, as well as on the scalp. Usually, there is only one lesion, but there may be several. This type of lesion may be present at birth or may become clinically apparent later in life.