Scanning electron microscopy of the endolymphatic sac epithelium.

In this study, scanning electron micrographs of the dog endolymphatic sac surface epithelium are presented. According to our morphological findings, three portions were recognized, the proximal, intermediate and distal part. The intermediate or 'rugose' portion was found the most differentiated where two types of cells were identified. These cells were seen to have many of the criteria for fluid absorption and phagocytosis. In man, alteration in the ability of these cells may lead to endolymphatic hydrops.