Capillary malformations

  • Chapter: Capillary malformations

    Article: 1 of 14

    Update: Mar 30, 2021

  • Author(s): Ott, Hagen

Capillary malformations (CM) are vascular anomalies that have existed since birth and are primarily due to dilatation of capillaries in the superficial dermis. They appear as sharply demarcated, patchy or planar, usually located at the level of the skin, light to dark red and sometimes bluish spots on the skin of variable shape and size.

According to the current ISSVA classification, capillary malformations of the skin and mucous membranes are also generally referred to as port wine stains, nevus flammeus or port wine nevus (although a color reminiscent of port wine only appears, if at all, during the course of the disease, usually in adulthood). Capillary malformation is distinguished from nevus simplex (syn. stork bite, angel's kiss), cutis marmorata telangiectatica congenita (CMTC), and teleangiectatic capillary malformations. Other classifications have been proposed by some experts which take greater account of clinical features and also genetic causes (see Happle in Recommended literature).

Although there is currently no consensus about classification, there is probably agreement among practicing physicians that by no means all capillary malformations of the skin appear as “port wine stains” (in the true sense of the word), but that “port wine stains” are one of several varieties of capillary malformations. In principle, a distinction must be made between capillary malformations occurring alone and those occurring in combination with other vascular malformations. In addition, isolated and syndromal forms are distinguished, some of which are associated with tissue abnormalities (mostly hyperplasia).

Classification of capillary malformations (based on ISSVA classification)

Cutaneous and/or mucosal capillary malformation (CM), usually non-syndromal
 CM with circumscribed overgrowth of bone and/or soft tissue
(including CM hemihyperplasia syndrome, diffuse capillary malformation with overgrowth, DCMO)
 CM with CNS and/or ocular anomalies (including Sturge-Weber syndrome)
 CM associated with arteriovenous malformation (CM-AVM)
 CM associated with microcephaly (MICCAP)
 CM associated with megalencephaly and polymicrogyria (MCAP)
 Hereditary hemorrhagic teleangiectasia (HHT)
Cutis marmorata telangiectatica congenita (CMTC)
Nevus simplex (syn. stork bite, angel's kiss)