Lectin-binding affinities of human breast tumors.

Paraffin-embedded sections from a variety of breast lesions were stained with a number of lectins labeled with fluorescein isothiocyanate and examined by fluorescence microscopy: 95 non-neoplastic tissues and 69 malignant tumors were examined. Lectin binding was demonstrated in all malignant tumors, the fluorescence being confined to the plasma membrane of the tumor cells. Normal and hyperplastic tissues either failed to stain or showed a grossly diminished level of fluorescence. The significance of the staining reaction is discussed.