Dark cell pathology in Menière's disease.

The dark cells in the cristae of the semicircular canals were studied histopathologically in 9 temporal bones from individuals with Menière's disease (MD group), 7 temporal bones with endolymphatic hydrops from individuals without a history of Menière's disease (non-MD hydrops group), and 10 normal temporal bones (control group). The density of the dark cells was significantly lower in specimens in the MD group versus the non-MD hydrops group (Wilcoxon's ranking test, t = 90.5, p less than 0.01) and control group (Wilcoxon's ranking test, t = 50.0, p less than 0.01), and many of the dark cells were found to be abnormal in the specimens from the MD group. The difference in dark cell density between the non-MD hydrops group and control group, however, was not significant (Wilcoxon's ranking test, t = 75.0), and few cells in these groups were abnormal. It is speculated that the differences in density and the abnormalities in dark cell morphology might be either factors in the etiology of endolymphatic hydrops or results of Menière's disease. Other, unknown, factors must be postulated to produce endolymphatic hydrops in ears with hydrops but without MD.