The electron microscopic examination of congenital keratoses of the oral mucous membranes: I. White sponge nevus

Abstract

A review of the literature concerning the reported cases of white sponge nevus and a discussion of other congenital white lesions of the oral mucous membranes have been presented. Five cases of white sponge nevus were examined by means of the light microscope and the electron microscope. One of the patients was a Negro, the first reported as such in the literature. The tonofilaments were observed in four patterns: (1) loosely dispersed throughout the cytoplasm, (2) perinuclear in distribution, (3) at opposite poles of the cytoplasm from the nucleus, or (4) in a circular mass in the center of an anucleoid cell. The cells of the spinous and more superficial layers often showed crystallization of the residual nuclear material and a loss of the nuclear membrane. Membrane-bound lamellated structures were noted near the outer cell membranes of many of the cells. The attachment plaques (desmosomes) appeared to have a normal morphology in most instances, although a number of altered attachments in the superficial cells were noted.