Ultrastructure of oral squamous-cell carcinoma.

Fresh surgical specimens of sixteen cases of oral squamous-cell carcinoma were processed for electron microscopic study. All cases were histologically graded as moderately differentiated carcinoma. As compared to normal oral stratified squamous epithelium, some unusual ultrastructural features were present in carcinoma. These features were spherical or ovoid nuclear bodies composed of concentrically arranged filaments and granules, clustered ribosomes, many lysosomal bodies, cell residues in other cells, absence and multilayering of basal lamina, pseudopodal cytoplasmic projections, microfilaments in peripheral cytoplasm, clusters of swirled tonofilaments, intracytoplasmic desmosomes, and a small amount of glycogen. These features are interpreted as being related to hyperactivity, phagocytosis, locomotion, and differentiation of cancer cells.