Histopathologic findings in surgical specimens of endolymphatic sac in Meniere's disease.

Two types of abnormality in the endolymphatic sac acquired at shunt surgery are presented. One was deep brown pigmentation in the subepithelial connective tissue. The pigment did not react to Prussian blue, thus ruling out hemosiderin. The other, in seven out of eight specimens, was the perisaccular fibrosis. The fibrotic foci in four cases were assumed, from the findings under ordinary illumination and polarized light microscopy, to be reorganized scar tissue.