A hemangioma, commonly known as a "strawberry birthmark", is the most common benign tumor of infancy. These vascular tumors grow very fast during the first year of life to the fear of the parents but then stop growing and actually get smaller very slowly during childhood so that they are usually gone by school age. Only in rare cases is any treatment needed. Congenital vascular malformations are the result of blood vessels not maturing (going to full development) while the infant is still in the mother's womb. If this happens early, the abnormal blood vessels do not have the form usually seen with blood vessels and appears more like a spongy mass which can involve neighboring body parts. If this happens later in the pregnancy, the blood vessels look more normal but are abnormally small, abnormally large or have unusually connections with other blood vessels. As a part of congenital vascular malformations, the venous malformation is the most common and possibly the easiest to manage. Congenital vascular malformations do not go away and will require a lifetime of care.