Birthmarks are congenital marks on the skin that appear at birth and occasionally disappears spontaneously. The term
nevus refers to a benign cutaneous tumor consisting of blood capillaries. Such tumors, which rarely spread from their original site and are not dangerous, vary in color according to whether the capillaries composing them carry arterial or venous blood. The popularly termed
cherry marks and
port-wine stains (shown below) are nevi on a level with the surface of the skin. Certain other vascular nevi, commonly known as
strawberry or
raspberry marks (scientifically known as
hemangiomas), are slightly elevated above the surface. These can appear anywhere on the body's surface, including the airway within the nose. The former Soviet ...