Significance of MiB‐1 staining in smears with atypical glandular cells

MiB-1 immunostaining may facilitate recognition of developing adenocarcinoma in cervical smear screening. In a retrospective analysis of prospectively collected data of 170 patients with atypical endocervical glandular cells and with repeat smears, archival Papanicolaou-stained smears were restained for MiB-1 and classified for the presence of preneoplastic changes of MiB-1 positive epithelial fragments. The results of classification based on MiB-1 positive epithelial fragments corresponded "roughly" with cytomorphological diagnoses. Of the 38 patients in which the primary smear was found to be MiB-1-positive, 12 of these persisted in the repeat smear. Thirty-eight of the 132 repeat smears of patients originally negative for MiB-1 pathology were positive. Of the total 50 MiB-1 positive repeat smears, four showed adenocarcinoma in situ on cytomorphological grounds. MiB-1 staining enhances detection of (pre)neoplastic changes. This approach does not destroy the morphology of the original smear and can be applied to routine material.