Disorders Affecting Cutaneous Vasculature

Abstract Disturbances can occur during the development of cutaneous vessels. These result in lesions that are called vascular anomalies. They are divided into vascular tumours and vascular malformations on the basis of clinical, radiological and histological aspects. Depending on the vessel type affected, the malformations are further divided into capillary, arteriovenous, venous and lymphatic malformations. The latter includes the group of variable primary lymphoedemas. Genetic testing is now added to the parameters used for diagnosis and classification. This has led to new group terms, such as PROS for PIK3CA‐related overgrowth syndromes and PIKopathies for vascular anomalies that have a mutation in the TIE2‐PI3K signalling pathway, as opposed to RASopathies with a mutation in the EPHB4‐RAS signalling pathway.