Progressive cochlear ossification secondary to Langerhans cell histiocytosis requiring sequential bilateral cochlear implantation: a case report

OBJECTIVES: Langerhans cell histiocytosis (LCH) is a rare disorder that may involve the temporal bone and, in rare cases, result in sensorineural hearing loss. This report highlights the importance of close radiological surveillance and timely cochlear implantation in the setting of progressive otic capsule ossification. METHODS: A 21-year-old male presented with a five-year history of progressive bilateral hearing loss, tinnitus, vertigo and imbalance. Following multidisciplinary team (MDT) discussion, cochlear implantation was deferred until completion of chemotherapy. RESULTS: Repeat CT imaging demonstrated progressive cochlear ossification involving the otic capsules. A repeat discussion followed, which led to an expedited cochlear implantation. The left side was implanted first due to lesser ossification, achieving full electrode insertion. Sequential implantation of the contralateral ear was performed four months later. However, insertion was limited due to advanced ossification. DISCUSSION: The second implantation was technically more challenging, with only partial electrode insertion possible due to advanced ossification. We advocate for close surveillance in the case of LCH to monitor for signs of otic capsule ossification. CONCLUSION: This case demonstrates that cochlear ossification in LCH may progress rapidly, narrowing the window for optimal implantation. Early cochlear implantation should be strongly considered in such cases.