Venous malformations.

Venous malformations are slow-flow congenital malformations. They consist of abnormal venous channels that do not involute. Venous malformations can either be superficial or involve deeper structures. Patients with venous malformations are often symptomatic. The most common complaint is pain from congestion, mass effect, or compression of neural structures. Swelling, compromise of function, and disfigurement are other common symptoms. Large lesions cause coagulopathy. Therapeutic options for the treatment of these patients include sclerotherapy, compression garments, and surgical resection. These complex patients are best treated in a multi-disciplinary clinic environment, as they require long-term follow-up throughout childhood into adulthood.