Adult-onset congenital cholesteatoma in the hypotympanum initially presenting as Bell's palsy: A case report.

INTRODUCTION: Cholesteatoma is a rare disease characterized by the accumulation of keratinized squamous epithelial cells in the middle ear or mastoid cavity. Vertigo and facial palsy, which are rare complications, may indicate erosion into the semicircular canals or the fallopian canal.

PATIENT CONCERNS: A 40-year-old woman presented to our clinic with progressive right-sided hearing loss over 5 years (primary concern). Approximately 10 years ago, the patient had developed acute right-sided facial weakness with no additional symptoms. A neurologist at another hospital had diagnosed her condition as Bell's palsy and treated it accordingly.

DIAGNOSIS: Adult-onset congenital cholesteatoma in the hypotympanum.

INTERVENTION: Combined endoscopic and microscopic removal of the cholesteatoma.

OUTCOMES: Physical examination revealed slight improvement in right-sided peripheral facial palsy.

LESSON: Routine eardrum examination is recommended for patients presenting with isolated peripheral facial palsy. If necessary, a patient should be referred to an otologist for further evaluation and treatment.