Vascular malformations are named based on the type of vessel that makes up the lesion. There are capillary, arterial, venous, and lymphatic malformations. Sometimes, vascular malformations occur as combined lesions, such as in Klippel-Trenaunay syndrome (lymphatic, venous, and capillary malformation).
Arterial Malformations
Arterial malformations often appear as a combined arterial-venous malformation. The lesion is usually purple and feels "full" beneath the skin. Often warmth and vibrations can be felt from the high blood flow. Arterial malformations can cause pain, bleeding, and ulceration for which treatment is required. Arterial malformations are often presurgically treated with a special radiology procedure to decrease flow in the vessels; this is done by an interventional radiologist, and surgical removal follows.
Capillary Malformations
Capillary malformations, previously referred to as port-wine stains, appear as flat pink or red stains on the skin. They are present at birth and typically remain throughout life (often becoming wartlike in nature) unless they are treated. Pulsed dye laser therapy often is effective at removing or lightening the discoloration. This is best done in infancy and often requires multiple treatments spaced several months apart.
Lymphatic Malformations
Lymphatic malformations have been referred to as cystic hygromas. They often involve the underlying muscle and/or bone and may cause swelling and bony overgrowth. Occasionally, clusters of very small fluid-filled blisters may develop on top of the skin and may weep. The size of lymphatic malformations may change with infection and/or trauma that results in bleeding into the malformation, and increased lymph flow through the region. Lymphatic malformations often are treated with a special procedure that is done by an interventional radiologist; this involves the injection of a medicine into the lymph vessel to help decrease the flow. Following this therapy, surgery to decrease the size of the malformation often is an option. For lymphatic malformations of the arms and legs, compression garments may help.
Venous Malformations
Venous malformations may affect the skin, muscle, and bone. They often appear as soft, easily compressive masses that have a blue tint. They often enlarge when placed in a dependent position. As the child grows, the malformation grows with them. The venous malformation often can be presurgically treated with a special radiology procedure that decreases the venous flow; this is done by an interventional radiologist. Surgery is another option for certain venous malformations.
View Children's Hospital's Vascular Anomalies Center brochure (PDF).
