The use of the lectin Ulex europeus to study epithelial cell differentiation in neoplastic and non-neoplastic oral white lesions.

Ulex europeus (Ulex 1) has been used to study the expression of cell surface alpha-L-fucose on oral epithelial cells of normal human mucosa, white lesions and carcinomas. In normal tissue and in 11 of 12 specimens of non-specific keratoses (leukoplakia), Ulex 1 stained epithelial spinous cells only. In 16 specimens of oral lichen planus, Ulex 1 labelled spinous epithelial cells, and in 12 there was also staining of the basal epithelial cells. Two specimens of white sponge naevus showed a total absence of epithelial staining with Ulex 1. Squamous carcinomas showed a loss of staining in the invading epithelial islands in six of eight specimens, but normal labelling of the surfaces of spinous cells at sites distant from the areas of epithelial invasion. When the severity of epithelial dysplasia, as assessed by the index of epithelial atypia, was compared with the pattern of staining of Ulex 1 in normal mucosa and white lesions there was no correlation. The results show that failure of Ulex 1 to stain cell surface carbohydrates may not be attributable to malignant transformation. The staining of cells not normally stained may be related to hitherto masked residues revealed by cell damage or altered differentiation.