Middle ear malformations combined with cerebrospinal fluid otorrhea

RATIONALE: Middle ear malformations (MEMs) encompass a diverse spectrum of congenital anomalies that significantly impair auditory function. They account for approximately 0.5% to 3% of conductive hearing loss cases, with etiologies involving both genetic and environmental factors. Clinically, MEMs complicated by cerebrospinal fluid (CSF) otorrhea are extremely rare. PATIENT CONCERNS: A 17-year-old male presented with right-sided hearing loss of over 7 years' duration. Otoscopic examination revealed a perforation in pars flaccid of the tympanic membrane. Pure-tone audiometry confirmed moderate conductive hearing loss in the right ear, while mastoid high-resolution computed tomography showed no obvious abnormalities. DIAGNOSES: Intraoperative observations revealed partial dehiscence of the vertical segment of the facial nerve canal, agenesis of the long process of the incus, and Hyrtl fissure with suspected CSF leakage from the bony defect. INTERVENTIONS: The patient underwent tympanic cavity exploration surgery, during which the fissure was repaired, a partial ossicular replacement prosthesis was implanted, and the ossicular chain was reconstructed. OUTCOMES: At the 45-day postoperative follow-up, the tympanic membrane perforation was closed, conductive hearing loss improved, and the air-bone gap was markedly reduced. LESSONS: To our knowledge, this represents the 1st reported case of MEMs complicated by presumed CSF otorrhea. The surgical intervention involving defect repair and artificial ossicle implantation significantly improved the patient's quality of life.