[Prognostic value of ultrastructural characteristics of dysplastic changes in the esophagus].

Dysplasia foci in the esophageal squamous epithelium against the background of various reactions of proliferation were studied by electron microscopy. Slightly altered tissue showed diverse cellularity, with dark cambial elements invariably present. With dysplasia advancing, the cell composition became uniform, with a high nuclear-cytoplasmic index. The dark cell pattern with numerous ribosomes was seen more often than that of keratinized clear cells. Small-cell focal proliferations are highly suggestive of precancer. Electron microscopy may be instrumental in eliciting more information on the risk of esophageal squamous epithelium precancer progressing to cancer since it provides data on cell composition, degree of cell differentiation and polysome formation as well as early signs of keratinization.