A case of Langerhans cell histiocytosis localized in the temporal bone, which presented as sudden sensorineural hearing loss: A case report and review of the literature.

Sudden sensorineural hearing loss is a condition marked by a rapid decline in hearing, defined as a decrease of 30 dB or more across three adjacent audiometric frequencies within 72 h. It can result from various factors, including ischemic events, infections, or tumors like meningioma and schwannoma, and in rare cases, may be linked to Langerhans histiocytosis, which involves an accumulation of specific immune cells. This document reviews literature and presents a case study of a 24-year-old male from Iran diagnosed with sudden sensorineural hearing loss due to Langerhans cell histiocytosis. The patient, who had diabetes insipidus, showed eosinophil-rich lesions with CD1a-positive, S100-positive, and Cyclin D1-positive cells. After 6 months of chemotherapy, there was no change in hearing levels. This case report underscores the importance of considering an occupying lesion in cases of sensorineural hearing loss, particularly when there are indications of additional paraneoplastic conditions.