Congenital vascular malformations: general diagnostic principles.

Venous malformation (VM) is the most common congenital vascular malformation (CVM), which usually presents as a single lesion in the majority of cases. It also presents as a mixed lesion combined with other CVMs (e.g. lymphatic malformation and arteriovenous malformation [AVM]). Therefore, the diagnosis of VM should include an appropriate work-up, to not only confirm and characterize the VM as either extratruncular or truncular but also to diagnose or exclude the presence of other CVMs. The diagnosis of VM can be made safely using non-invasive to minimally invasive studies, which can also distinguish VM from infantile haemangioma. Invasive studies, such as venography and arteriography, are generally reserved for therapeutic planning and diagnosis of more virulent CVMs (e.g. AVM). The work-up of VM should include a complete assessment of the extent and severity of the primary VM lesion. In addition, its embryologic origin, as well as its haemodynamic characteristics and secondary effects should also be determined.