Breast tumor diagnosis in cytologic aspirates using monoclonal antibodies to keratin 8 and 17

OBJECTIVE: To determine the effect of double immunostaining in the differential diagnosis of the benign vs. malignant nature of breast lesions with fine needle aspiration results. STUDY DESIGN: The study group consisted of 26 samples aspirated from patients with borderline breast lesions. RESULTS: Direct immunostaining by means of monoclonal antibodies directed against individual intermediate filament proteins keratin 8 and 17 revealed that the percentage of K8(+)K17(+) cells in material from patients with fibrocystic disease and fibroadenoma significantly exceeded that found in carcinoma specimens. The diagnoses were confirmed histologically. CONCLUSION: The quantitative method applied in the analysis of double-immunostained cytologic aspirates is recommended for the differential diagnosis of the benign vs. malignant nature of breast lesions in borderline cases.