Oral leukoplakia: a scanning electron microscopic study of epithelial surface patterns

Biopsies from oral leukoplakias of different anatomic locations were studied by light- and scanning electron microscopy. Clinically, 11 cases showed the homogenous, flat type, and 3 represented the inhomogenous, nodular type of oral leukoplakia. The surface patterns of lining epithelial cells, as well as the cut surface structures were compared with those obtained by light microscopy. The results were compared with other published findings of normal oral mucosa, oral leukoplakia, oral carcinoma, and lesions of the uterine cervical mucosa. The epithelial surface cells revealed micropatterns comparable to normal ortho- or parakeratotic cells in the cases of homogenous oral leukoplakia. Biopsies showing varying degrees of dysplasia revealed cell surfaces with irregular microvilli or swollen microridges; cell forms also showed varying profiles and shapes as well as pleomorphism. Cell desquamation was seen in all cases. Since cell maturation and differentiation is linked to a specific surface morphology, SEM has to be considered as a further valuable diagnostic method.