Morphometric Analysis of the Human Endolymphatic Sac:Section 1. Evaluation of Epithelial Organization of Sacs from Four Normal-Hearing Cases

The height of epithelial cells in the pars canalicularis (intraosseous endolymphatic sac) was measured at four different superior-to-inferior levels of four sacs from 4 normal-hearing adults. We found that the lumen of the canaliculi was lined predominantly with cuboidal cells; there were also squamous and columnar cells. There was a significant association between cell height and canalicular size: epithelial cells lining small canaliculi tended to be taller than epithelial cells lining large canaliculi. This association was not consistent at all superior-to-inferior levels of the sac. This inconsistency of the association indicates that the pars canalicularis is organized into different functional regions.