Lectin binding patterns in benign and malignant lesions of the breast

The binding patterns of a panel of eight lectins were studied in twenty eight breast lesions, consisting of ten cases of fibroadenoma, three cases of cystosarcoma phyllodes, five cases of fibrocystic disease and ten cases of infiltrating duct carcinoma by light microscopy. The eight lectins viz. PNA, WGA, RCA, SBA, UEA I, LTA, LCA and Con A were tested on paraffin sections using the Avidin Biotin Peroxidase Complex technique. PNA, RCA and UEA I showed a consistent positivity in benign and malignant lesions. The binding was localised mainly along the apices of mammary ductal epithelial cells in the benign lesions. In contrast, the malignant cells showed a considerable variation in staining patterns like diffuse cytoplasmic, membranous, and vacuolar. No definite correlation was seen between the intensity of binding and the histological grade in infiltrating duct carcinoma except in the case of Con A which was seen to bind more intensely to poorly differentiated tumours. The diagnostic significance of these patterns have been discussed.