Lectin histochemistry of normal lung and pulmonary adenocarcinoma

In order to evaluate the staining pattern of glycoconjugate profiles in adenocarcinomas of the lung, pulmonary adenocarcinomas were classified according to their: (a) degree of differentiation; (b) cellular subtyping and mucus secretion; and (c) immunohistochemical characteristics. Studies were performed on 42 pulmonary adenocarcinomas using eight lectins. Formalin-fixed, paraffin-embedded tissues were stained with avidin-biotin peroxidase complex methods. Four lectins [wheat germ (WGA), succinylated WGA (SucWGA), peanut (PNA) with neuraminidase (N) treatment, and Ricinus communis (RCA-I)] showed strong positive staining reactions in well-differentiated adenocarcinomas. Bronchial surface epithelial type, one of the subtypes among 26 cases of well- and moderately differentiated adenocarcinomas, displayed strong positive staining for WGA, SucWGA, PNA N(+), RCA-I, and Bandeirea simplicifolia (BSA-I). Goblet cell types stained positive for all lectins except Dolichos biflorus (DBA). Bronchial gland cell types also showed a strongly positive stain for WGA, SucWGA, soybean (SBA), PNA N(+), RCA-I, and Ulex europaeus (UEA-I). The lectin positive staining reaction was related to the degree of mucus secretion within the tumor cells. These results revealed that the glycoconjugate profile of pulmonary adenocarcinomas was basically sialic acid, together with N-acetyl-glucosamine and beta-D-galactose. The observation that UEA-I showed a strong staining reaction in mucus-producing adenocarcinomas, such as goblet cell and bronchial gland cell types, indicates that localization of alpha-L-fucose may be a specific carbohydrate from non-mucus-producing pulmonary adenocarcinomas.