Coexistence of Temporal Bone Fibrous Dysplasia and External Ear Canal Atresia: Challenges in Diagnosis

Abstract

Temporal bone fibrous dysplasia (TBFD) typically manifests with varying degrees of external auditory canal involvement, often leading to complete canal stenosis. The coexistence of ear canal atresia and cholesteatoma in TBFD is a rare finding. Case ReportA 25-year-old woman presented with symptoms of impaired hearing, otalgia, and aural fullness. Otoscopy revealed complete stenosis of her left ear canal, with a blind pouch at the bony-cartilaginous junction. Pure Tone Audiometry indicated a 63.65 dB air-bone gap (ABG) at 500, 1000, 2000, and 4000 Hz in her left ear. Non-contrast HRCT of the temporal bone showed classical pagetoid fibrous dysplasia isolated to the left temporal bone, along with a soft tissue density mass in the residual medial end of the external canal and middle ear, and a vestigial external opening was observed at the outer meatus. Intraoperatively, cholesteatoma was detected in the medial end of the external auditory canal, lateral to the retracted tympanic membrane. The patient underwent subtotal petrosectomy, with obliteration of the middle ear and mastoid using abdominal fat, and blind sac closure of the EAC. Post-operative follow-up has been uneventful to date. ConclusionTemporal bone fibrous dysplasia causing complete stenosis of the ear canal with a blind skin pouch externally remains unexplained. Intraoperative evidence of atretic ear canal can explain its coexistence with temporal bone fibrous dysplasia, which develops later. Subtotal petrosectomy combined with blind sac closure of the external auditory canal may serve as an alternative single-stage procedure for achieving a trouble-free long-term outcome.