Successful En Bloc Resection with Acceptable Cosmesis of a Right Recurrent Giant Scalp-Orbital AVM Causing Severe Disfigurement: A Case Report
Scalp Arterio Venous Malformation (AVM) is a rare congenital entity, accounting for only 8.1% of all AVM cases.  These lesions are made up of an abnormal fistulous tangle of tortuous dysmorphic network of vessels “vascular nidus” directly connecting between the feeding arteries and draining veins, without capillary connection, located within the incision subcutaneous layer.
With time, these congenital lesions may evolve and enlarge and clinically manifest with variable features. The only effective method of preventing evolution of these malformations is to exclude the lesion completely from the circulation. Generally, scalp AVM presents as a small pulsatile mass; but with time, if untreated, it will progressively enlarge and spread to the entire scalp, giving a grotesque appearance and involves the craniofacial structures and skull bone and even extends intra cranially, leading to seizures and hemorrhages. Involvement of the orbit and face may cause severe facial disfigurement, proptosis, visual obstruction and even facial palsy. These lesions may be complicated by ulceration, infection and profuse bleeding.
There are varieties of neuro-imaging modalities which help in characterizing the structural complexity, location and the extent of the lesion and assist in appropriate preoperative surgical planning. Among them, Three-Dimensional CT Angiography (3D-CTA) is regarded as the cornerstone for investigation.
Management of these complex lesions may require multidisciplinary approach with preoperative embolization and surgical excision. As it is often difficult to cure scalp AVM with embolization alone, surgical resection is usually required. Generally, surgical excision is said to be curative; and recurrence is uncommon after complete resection.
We present a rare case of a recurrent congenital scalp-orbital AVM causing proptosis, visual hindrance and severe facial disfigurement which was successfully excised with acceptable cosmesis along with a brief literature review.