Endolymphatic duct and sac in patients with Meniere's disease. A temporal bone histopathological study

The endolymphatic ducts and sacs of 25 temporal bones with idiopathic endolymphatic hydrops from individuals with Meniere's disease were studied and compared with the same number of control bones without endolymphatic hydrops from individuals with no premortem history of otologic disease. The control bones were selected so that the sizes of their vestibular aqueducts matched those temporal bones from individuals with Meniere's disease. The endolymphatic ducts and sacs of all bones were studied by the medial view graphic reconstruction method and/or histological observation under a light microscope. In the endolymphatic duct and sac of many of the temporal bones from patients with Meniere's disease were noted a diminution of the width of the endolymphatic duct in its isthmus portion, an increase in the area of the collapsed lumen of the endolymphatic sac, fibrotic changes in the perisaccular loose connective tissue, and an increase in the quantity of intraluminal eosinophilic material. The frequencies with which these pathological findings were noted in bones from individuals with Meniere's disease and in control bones were statistically significantly different. No significant differences were observed under light microscopic study between these two groups with regard to the condition of the epithelial cells, the degree of rugosity of the endolymphatic sac, or the appearance of melanin-like pigmentation of hyalinization in the perisaccular connective tissue.