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.