Cirsoid aneurysm

A cirsoid aneurysm is the dilation of a group of blood vessels due to congenital malformations with AV (arterio venous) shunting.

Cirsoid means resembling a varix. Sometimes, a minor traumatic episode, such as a fall or bump on the head, can lead to the formation of a cirsoid aneurysm. Often these are trivial traumatic episodes

It most commonly occurs over the head usually the superficial temporal artery. It can also occur in places where medium vessels lie over bones without much intervening tissues between them and the skin.

The superficial temporal artery is the most commonly involved artery.