Capillary malformation/arteriovenous malformation

Revencu, Nicole [UCL] Boon, Laurence M. [UCL] Vikkula, Miikka [UCL]

Vascular anomalies are a heterogeneous group of disor- ders divided into tumors and malformations based on clinical, radiologic, and immunohistochemical studies. Vascular malformations are considered to be localized defects of vascular morphogenesis. They are present at birth, even if not always visible, and based on the type of the affected vessel, they are classified into capillary, venous, arterial, and lymphatic malformations. Some- times, more than one vessel type is involved (combined vascular malformations), such as arteriovenous malfor- mation, capillary–venous malformation, etc. Vascular malformations are in general sporadic, but familial forms exist, enabling genetic studies and the identifi- cation of genes involved in vascular morphogenesis, which can lead to proper genetic counseling and devel- opment of targeted therapies. This chapter reviews sporadic and familial capillary malformation with a special emphasis on cerebral cavernous malformation and capillary malformation–arteriovenous malforma- tion. Hereditary hemorrhagic telangiectasia is discussed in Chapter 49.