BREAST-TUMOR DIAGNOSIS IN CYTOLOGIC ASPIRATES USING MONOCLONAL-ANTIBODIES TO KERATIN-8 AND KERATIN-17

OBJECTIVE: To determine the effect of double immunostaining in the dif ferential diagnosis of the benign vs. malignant nature of breast lesio ns 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 antibo dies directed against individual intermediate filament proteins kerati n 8 and 17 revealed that the percentage of K8(+)K17(+) cells in materi al from patients with fibrocystic disease and fibroadenoma significant ly exceeded that found in carcinoma specimens. The diagnoses were conf irmed histologically. CONCLUSION: The quantitative method applied in t he analysis of double-immunostained cytologic aspirates is recommended for the differential diagnosis of the benign vs. malignant nature of breast lesions in borderline cases.