The ultrastructure of the endolymphatic sac in Ménière's disease.

Meniere's disease is a well recognized clinical entity, yet the etiology and pathophysiology of the disease is not fully understood. Impaired endolymphatic sac function resulting in faulty reabsorption of endolymph has been implicated in the production of the disease. The histopathological findings from biopsied sac specimens and observed by transmission (TEM) and scanning (SEM) electronmicroscopy in two patients with early Meniere's disease are presented and discussed. Extensive subepithelial fibrosis with loss of vascularity and obliteration of portions of the lumen of the endolymphatic sac by an ingrowth of collagen is noted in both specimens. The implications of these findings are discussed and the need for more TEM and SEM studies of inner ear disorders is stressed.