Vascular malformations. These are congenital malformations that consist of capillary, venous, arterial, or lymphatic abnormalities. There are often combined alformations that comprise different types of vessels. Examples of vascular malformations include port-wine stains (capillary malformation), cystic hygroma (lymphatic malformation), and venous malformations. Vascular malformations are present at birth and grow proportionately with the child. Some vascular malformations may not manifest themselves until adolescence or adulthood. These figures represent venous malformations on the hand and foot.