Vascular anomalies are normally classified in two different groups: malformations or tumours. They are often confused, especially when it comes to diagnosis.
Vascular malformations occur because of an error in the development of vascular embryogenic tissue, meaning that they are present at the time of birth. Vascular tumours, on the other hand, appear after birth (except congenital haemangiomas), within a period that can vary from a few weeks to several months or many years.
In this book, we will describe tumours and malformations as different entities, focusing our attention on vascular tumours.