A case report of infantile arteriovenous malformation of the masseter muscle

Abstract

 Arteriovenous malformation (AVM) is a congenital vascular abnormality characterized by a direct connection between an artery and vein without normal capillary beds, which is called a nidus, and which is reported to be rare in the head and neck region. We report a case of infantile AVM of the masseter muscle in a 12-year-old male with a complaint of a soft and painless mass measuring 3.5×3.5 cm, in the left mandibular region, which becoming erect on clenching and in which vascular bruit-like sound could be heard. AVM of the masseter muscle was diagnosed based on the imaging findings of ultrasonography, enhanced CT and MRI. Notably, the 3D–CT angiography findings showed that the feeding artery was a left transverse facial artery followed by a nidus with venous drainage into the left masseteric vein in the left masseter muscle. Surgical removal was performed via an extraoral approach. The postoperative course was without complications and there has been no sign of recurrence until now. AVM generally requires treatment in the early stage due to its lack of natural regression. The preoperative evaluation of the related vessels by 3D–CT angiography is necessary for surgery which is considered to be the treatment of choice when possible.