Cytostructural localization of peanut lectin binding in fine‐needle aspirates of benign and malignant breast lesions

Numerous studies have employed lectin binding patterns to investigate alterations in cell surface polysaccharide expression associated with malignant transformation. Cytostructural relocalization of peanut lectin (Arachis hypogaea) binding sites from the cell surface to the cytoplasm has been described in breast carcinomas. To investigate the possible utility of peanut lectin binding patterns in the diagnosis of breast fine‐needle aspirations, the PNA immunoperoxidase method was applied to smears from a group of 15 benign and malignant breast lesions. Cytostructural relocalization of PNA binding was seen in both benign and malignant breast lesions, indicating that it is of little diagnostic utility in the assessment of malignancy. This finding was noted in both cytologic and histologic preparations. Diagn Cytopathol 1987;3:310‐3.