The right endolymphatic sac consisted of a flat lining of columnar epithelial cells on a thin fibrovascular stroma. Within the center of the lumen, there was a large amount of mineralized material. In some areas, the right endolymphatic sac lining was mildly hyperplastic and there were multiple foci of granulomatous and granulocytic inflammation (H&E stain, 10x objective).
