A<unk>  is any of a range of lesions from a simple birthmark to a large tumor that may be disfiguring. They are caused by a disorder of the<unk>  system. A<unk>  is a localized defect in blood or lymph vessels. These defects are characterized by an increased number of vessels, and vessels that are both enlarged and sinuous. Some<unk> es are congenital, others appear within weeks to years after birth, and others are acquired by trauma or during pregnancy. Inherited<unk> es are also described and often present with a number of lesions that increase with age.<unk> es can also be a part of a syndrome. The estimated prevalence of<unk> es is 4.5%.<unk> es can occur throughout the whole body, but in 60% of patients they are localized in the head and neck region.<unk> es can present in various ways, when situated deep below the skin, they appear blue, and are often called cavernous. Superficial<unk> es appear as red-coloured stains and are associated with<unk> es affecting the dermis. Historically,<unk> es have been labeled with descriptive terms, according to the food they resembled (port wine, strawberry, cherry, salmon patch). This imprecise terminology has caused diagnostic confusion, blocked communication and even caused incorrect treatment, as it does not differentiate between various<unk> es. However, in 1982, Mulliken introduced a classification that replaced these descriptive terms and gave direction to the management of various<unk> es. This classification, based on clinical features, natural history and cellular characteristics, divides<unk> es into two groups:<unk>  tumors and<unk>  malformations. Although<unk>  tumors and<unk>  malformations can resemble each other, there are important differences between both.
Vascular anomaly
Vascular malformation
Congenital vertebral anomaly
Musculoskeletal abnormality
Genetic disorder
Congenital heart defect
Vascular occlusion
Metabolic disorder