Identity of growing pulsatile mass lesion of the scalp after blunt head injury: Case reports and literature review.

A growing pulsatile lump of the scalp rarely occurs after blunt head injury. In this condition, the lump may be a delayed-onset traumatic vascular scalp injury such as a pseudoaneurysm or an arteriovenous fistula (AVF). We describe two cases of delayed-onset traumatic vascular scalp injuries: one involved a pseudoaneurysm of the superficial temporal artery, and the other, an AVF fed by the occipital artery. We reviewed reported cases of delayed-onset traumatic vascular scalp injury and discuss the features, diagnosis and treatment. When a growing lump of the scalp is encountered, ultrasonography may be useful in searching for vascular injuries.