Lectin-binding patterns in normal, hyperplastic and neoplastic endometrium: the prognostic value of concanavalin A

Lectins are proteins and glycoproteins of nonimmune origin which bind speci fically to carbohydrate residues. agglutinate cells and/or precipitate comp lex carbohydrates. Lectin-binding patterns in normal, hyperplastic and neop lastic endometria were studied using four biotinylated lectins (Con A, LCA, e-PHA, 1-PHA) and the avidin-biotin-peroxidase technique. Canavalia ensifo rmis agglutinin (ConA) and Lens culinaris agglutinin (LCA) reacted strongly with the luminal borders and the cytoplasm of epithelial cells but, whilst in normal and benign endometrial tissues the cytoplasmic staining was conf ined to the apical and the basal aspect of the cells, in endometrial carcin omas and in some atypical hyperplasias lectin binding also occurred in the lateral cytoplasm (Con-A-lat), although in differing proportions of cells. Interestingly, extensive Con-A-lat in the tumour cells was much more freque nt in non-endometrioid carcinomas (P<0.05) and was significantly associated with poor histological differentiation (P<0.0001), low oestrogen and proge sterone receptor content (P<0.01 and P=0.0001, respectively) and an unfavou rable long-term survival (P<0.05). With Phaseolus vulgaris erythroagglutini n (e-PHA) and leucoagglutinin (l-PHA) a linear, rather inconsistent, staini ng at the level of the basement membranes was observed in the glands: this, also noted with LCA, appeared intact in normal and hyperplastic glands wit hout cytological atypia, and fragmented or absent in malignant glandular st ructures and in most hyperplastic glands showing cytological atypia. It is concluded that changes in the distribution of lectin-binding molecules in t he endometrial cells are associated with the malignant state, whilst the ex tent of Con-A-lat reflects the biological behaviour of the tumours.