Upgrading unsatisfactory cervical smears with the MiB-1 method.

When an unsatisfactory smear (thick inflammatory infiltrate or blood influencing the staining characteristics of the epithelial cells) is restained for MiB-1, the diagnostic proliferating cells are visualized, and the MiB-1-positive smears can be thus upgraded as borderline, grade I, II, and III, corresponding with the cytologic diagnoses of, respectively, ASCUS, CIN I, II, and > or = III. In a period of 18 months, 2,068 unsatisfactory smears out of a material of 84,817 smears were restained for MiB-1. In the unsatisfactory group, significantly more abnormal smears were detected than in the satisfactory group. Seventy-five of the unsatisfactory group were biopsied because of the MiB-1 findings: Three women proved to have severe dysplasia, four had carcinoma in situ, and three had invasive carcinoma. The per mileage for invasive cervical carcinoma was ten times larger in the unsatisfactory group than in the satisfactory group; thus the MiB-1 method has further enhanced our diagnostic acumen in this difficult type of smears.