Definition:

Venous malformations are vascular anomalies that present with congenital blue-colored birthmarks resulted from dilated veins. Venous malformations are low-flow vascular malformations. Majority of them occur in the head and neck region. Birthmarks in cutaneomucosal venous malformation appear mainly on skin and mucosa, whereas plaques in glomuvenous malformation are located on the extremities, usually nodular and associated with abnormal smooth muscle-like 'glomus cells'. Most cases are unifocal, with extensive venous malformations accounting for only one percent of cases and more commonly manifesting as rare, inherited forms. Venous malformations will grow with age, infiltrating normal structures. They can give rise to functional disabilities, including obstruction to airway and swallowing difficulties. Also, they can cause visual or auditory disturbance and delayed speech development. In addition, bleeding, pain, infection, skeletal deformity, and cosmetic disfigurement may occur. Active treatment of venous malformations is indicated especially in head and neck region. Surgery can cause damage to normal surrounding structures, resulting in significant disfigurement and loss of function. Complete excision is often impossible for infiltrative lesions. Sclerotherapy has gained popularity recently and become the first-line treatment for venous malformations in head and neck region.