Pulsatile Tinnitus Associated With a Rare Congenital Vascular Anomaly: A Case Report

Pulsatile tinnitus (PT) is an uncommon form of tinnitus.Unlike non-pulsatile tinnitus, PT is often unilateral and may have a vascular origin, warranting imaging evaluation to identify its underlying cause.Dehiscence of the bony wall of the internal carotid artery (ICA) canal, with protrusion of the artery into the middle ear, is a rare cause of a pulsatile retrotympanic mass and may be the underlying cause of PT.Because it can mimic other middle-ear pathologies, accurate imaging is essential before any surgical intervention is considered.Congenital absence of the external carotid artery (ECA) is a rare anatomical variant.We report the case of a 39-year-old man with progressive bilateral hearing loss and left PT, in whom a pulsatile retrotympanic mass was found on otoscopy.Computed tomography (CT) of the temporal bone, CT angiography, and time-resolved magnetic resonance angiography revealed a dehiscent left ICA canal, together with an incidental congenital absence of the left ECA and stenosis of the proximal C2 segment of the left ICA.This case highlights the role of imaging in the evaluation of PT and the importance of recognizing rare carotid variants and their potential clinical implications.