Clinicopathologic case report: ultrastructure of the epithelial dystrophy of Meesmann.

As in previous studies of Meesmann dystrophy, intense vacuolation of the epithelium was observed. However, neither histochemical nor electron microscopical examination of the specimens showed any evidence of abnormal quantities of glycogen or the electron dense peculiar substance of Kuwabara and Ciccarelli. Electron microscopy indicated that the basic alteration leading to the manifestations of the dystrophy was electron dense bodies in the cytoplasm of the basal epithelial cells. These electron dense bodies appeared similar to lysosomes. In the more superficial cell layers, the electron dense bodies were engulfed by vacuoles that gradually increased in number and size to fill the cytoplasm and, finally, destroyed the most superficial cells.