Sudden hearing loss in chronic myelogenous leukaemia implicating the hyperviscosity syndrome

Sudden sensorineural hearing loss that presents as the initial sign of haematological disease is very rare. Chronic myelogenous leukaemia has been implicated as a causative factor of sudden sensorineural hearing loss. A 49-year-old male presented with unilateral sudden sensorineural hearing loss. The patient was found to have chronic myelogenous leukaemia during a work-up for his hearing loss. We present a case of a chronic myelogenous leukaemia patient whose first manifestation was sudden sensorineural hearing loss. We presume that cochlear vessel occlusion as a result of elevated blood viscosity was responsible for this patient's hearing loss. Early onset of sudden deafness in a chronic myelogenous leukaemia patient may be due to the hyperviscosity syndrome and it may be possible to reverse hearing loss through early leukapheresis.