Embolization of a congenital arteriovenous malformation arising off the internal mammary artery.

Congenital arteriovenous malformations (AVM) of the internal mammary artery (IMA) are exceptionally rare. Patients with AVMs arising off the left IMA may present with continuous precordial murmurs and/or a pulsatile chest mass. AVMs in this location pose a risk of enlargement, rupture, infection, or high-output cardiac failure. The potential risks associated with AVMs warrant early therapeutic intervention. We describe a case of a congenital AVM originating from the left IMA, which was successfully embolized with n­butyl cyanoacrylate (NBCA) using a transcatheter arterial approach.