Paraneoplastic syndrome: a masquerade of autoimmune inner ear disease.

Rare and diagnostically challenging, paraneoplastic syndromes can appear months to years before detection of their underlying neoplasms and are associated with rapidly progressive neurologic deficits, including cochleovestibulopathy and death. Less than 20 cases of paraneoplastic cochleovestibulopathy have been reported in the online database PubMed. We present three recent cases: one patient with a history of B-cell follicular lymphoma who developed dermatomyositis and hearing loss before detection of lymphoma recurrence in his anterior chest wall, a second patient with sudden asymmetric hearing loss, found to have a 12-cm renal mass before death, and a third with fluctuating bilateral hearing loss who was ultimately found to have a thymoma. Although characterized as type VI (non-immune rapidly progressive sensorineural hearing loss) within the Harris autoimmune inner ear disease classification system, the mechanism of paraneoplastic cochleovestibulopathy is not well understood. Although specific anti-neuronal antibodies such as anti-Hu may be associated with other paraneoplastic neurologic disorders, these antibodies have limited diagnostic utility with paraneoplastic cochleovestibulopathy. Steroids have limited efficacy with regard to hearing recovery, whereas intravenous immunoglobulin has been shown to be of benefit. These recent cases demonstrate how auditory and vestibular deficits may be indicative of a rare but potentially life-threatening occult neoplasm where timely diagnosis is critical. We believe that understanding paraneoplastic cochleovestibulopathy is of interest across a broad range of clinical practices.