Venous malformation and haemangioma: differential diagnosis, diagnosis, natural history and consequences.

Venous malformation (VM) is the most common form of congenital vascular malformation (CVM). VM presents at birth as an inborn vascular defect and never disappears/regresses spontaneously through the rest of life; it will continue to grow slowly at a rate that is proportional to the growth rate of the body. Haemangioma is not a vascular malformation but one of the vascular tumours originating from the endothelial cells; it develops after birth mostly in the infantile/neonatal period with a distinctive growth cycle: a proliferation phase of early rapid growth followed by an involutional phase of slow regression. Although the vascular malformation and vascular tumour belong to the 'vascular anomaly' together, both conditions are fundamentally different not only in their anatomical, histological and pathophysiological findings but also in their clinical courses. Therefore, an appropriate differential diagnosis of the VM is mandated not only from other kinds of CVMs but also from 'genuine' haemangioma. Appropriate diagnosis and assessment of VMs can be made based on clinical presentation and a proper combination of basic non-invasive studies in general but the presence of a mixed lesion involving other types of CVM lesions and the type of VM lesion, extratruncular and truncular, will dictate the need for further work-up with additional non- to less-invasive study or angiography. Otherwise, angiography is usually reserved for therapeutic planning and treatment.