[Lectin histochemical studies of nevus cell nevi of the corium].

Using 11 different kinds of lectins, we histochemically studied 18 dermal nevocytic nevi (NCN). The investigation included both unfixed frozen sections and pretreated sections fixed with acetone (pretreatment: chloroform/methanol, Triton X-100, neuraminidase). In this way, we hoped to get some information both on the expression of surface glycoconjugates and the chemical nature of the sites of lectin binding. Our results argue for an abundance of glucosyl, mannosyl, galactosyl, and N-acetyl galactosamine residues on the surface of nevus cells. In comparison to keratinocytes, we found a greater sensitivity to chloroform/methanol, which suggests a relative increase of glycolipids. Dermal NCN showed heterogenic lectin binding: The highest intensity was seen in the marginal nevus cells, the lowest in the central cells of epidermal nests. Dermal cells showed a moderate binding intensity. Epidermal cells lying above the NCN disclosed some modifications of their lectin binding pattern. In contrast to normal epidermis, basal keratinocytes failed to bind LCA; suprabasal cells showed cytoplasmic staining. In some NCN, we observed an intensive perinuclear staining of the upper keratinocytes with granular ConA. Our results suggest (1) a modified lectin binding pattern of nevus cells depending on their microenvironment, as well as (2) a distinctly altered lectin binding of keratinocytes in the adjacent epidermis.