Vascular malformations (VMs) are abnormal blood vessels that develop before a baby is born. A person may have an increased number of blood vessels or misshaped vessels.
The cause of these malformations is unknown. Both males and females are equally affected.
Although vascular malformations are present at birth, they may not be seen or found until weeks or years later. Vascular malformations increase in size proportionally (at same rate) as a child grows. Some malformations may become larger around growth spurts including puberty.
Vascular malformations do not go away over time. Usually malformations cannot be entirely removed by surgery.