Venous malformations vary in size and location within the body. These vascular anomalies are are “slow-flow vascular malformations” and are the result of abnormalities in the development of veins. Skin or tissue immediately below the skin may be affected, appearing as a light blue colored “stain” with or without swelling. Venous malformation can vary in size over time, this is due to swelling within the malformation. Venous malformations are present at birth, and grow in proportion to the child. Some venous malformations may be deeply located, and not visually apparent. In these cases, a MRI and/or ultrasound may be recommended to “visualize” the malformation.
An arteriovenous malformation (AVM) is a vascular lesion (localized or diffuse) that consists of direct connections between arteries and vein and absence of the intervening capillary bed. This results in the abnormal flow of blood from the arteries directly into veins. Lesions that are localized are commonly seen on the head and neck. These lesions may appear as light vascular stains at birth. Localized lesions, most commonly seen on the head and neck, often appear as light vascular stains at birth. Diffuse lesions, are more commonly seen on the trunk or on a limb. Diffuse lesions may not be observed until later childhood as they increase in size with age.
Hemangioma (from the Greek “haema = blood”, “angeio=vessel and “-oma=tumor”), are infant benign tumors. Infantile hemangiomas occur in approximately 5-10% of infants. Infantile hemangiomas are more frequently seen in females, premature infants, and infants with low birth weights. Hemangiomas appear within the first weeks of life. These benign tumors may grow rapidly during the first 3-6 months of infancy, with approximately 80% of growth achieved within the first 3 months. Typically, growth of the hemangioma is complete at approximately 12 months, with involution (spontaneous shrinking) of the tumor beginning after growth is complete. Involution will continue slowly over several years. A large number of hemangiomas regress by 5 years of age. Although many of these benign tumors regress in size over time, some may leave residual redundant fibrofatty tissue, a scar, or residual telangiectasia (small dilated blood vessels near the surface of the skin).
Port Wine Stain
Almost always called a “birthmark” or “firemark”, a port-wine stain is caused by a vascular anomaly. This vascular anomaly is due to abnormal aggregation of capillaries. Port-wine stain derives its name from their coloration, similar to a Portuguese fortified red wine.