[Classification of vascular abnormalities and neoplasms]

Vascular malformations and neoplasms are very common skin disorders, found in up to 5% of newborns. However, a clear distinction has to be made between proliferating vascular lesions and permanent malformations. An exact classification is also extremely useful, since many new specific diagnostic and therapeutic measures have been developed in recent years. True proliferating tumors are, for example, childhood hemangiomas, glomus tumors, granuloma pyogenicum, tufted angiomas, senile angiomas, and malignant vascular lesions. Vascular malformations can affect capillaries, veins or arteries, as well as lymphatic vessels. Arteriovenous shunts and combined malformations may also exist (Hamburg classification). Nevi flammei, nevi anaemici, hematolymphangiomas, angiokeratotic nevi, circumscribed venous-arterious malformations, and the blue-rubber-blebnevus-syndrome may either be infiltrating or circumscribed and are characterised by a persistence of the primitive vessel network. In contrast, other malformations involve various vascular trunks, showing vessel dilation or obstruction, often combined with changes in bone or soft tissue. Significant large vessel malformations are the Bockenheimer syndrome, the Klippel-Trenaunay syndrome and the Parkes-Weber syndrome. Combinations involving both large trunks and extravascular space such as the Klippel-Trenaunay syndrome also occur.