"Endolymphatic sacitis" in a case of active Menière's disease. An ultrastructural histopathologic investigation.

An ultrastructural analysis of an entire intraosseous endolymphatic sac (ES) from a patient with active, well-documented Menière's disease was performed for the first time. The results were compared with those obtained from ES biopsy material from patients with acoustic neuromas. The ES was small in size and showed signs of focal inflammation with intraepithelial invasion by mononuclear cells. At these places the normal fine structure, including the vascular anatomy, was altered. The possible relationship between these changes and Meniere's disease is discussed.