Changes in the audiograms of a nasopharyngeal cancer patient during the course of treatment: a temporal bone histopathological study.

This report shows the changes that occurred in consecutive audiograms of a patient who underwent chemotherapy and radiotherapy for nasopharyngeal cancer and the histopathological examination of the temporal bones. Both conductive and sensorineural hearing loss developed, but followed different modes of progression. In the left ear, an air-bone gap appeared and deepened, while in the right ear, severe conductive hearing loss was present upon admission and improved after treatment. Sensorineural hearing loss was worse in the right ear, but deteriorated gradually in both ears. Histology revealed tumor invasion in the right temporal bone. Both middle ears showed effusion, but no radiation-induced changes that may be responsible for the conductive loss. The main changes in the cochlea were vascular stria degeneration, spiral ligament atrophy, and spiral ganglion cell depletion, while the hair cells were only occasionally missing. Apart from confirming what has been established previously by other authors, some interesting findings were observed: (1) in addition to the high frequency hearing loss typically caused by cis-platinum and by radiation, there was also low frequency hearing loss, and (2) the cochlear damage was most severe in the vascular stria and spiral ganglions, sparing the hair cells.