Individual abnormal cervical epithelial cells can be categorized either by the lesion from which they are derived or by their unique cytologic characteristics. In building a data base for image analysis of cervical epithelial cells, categories of cells were defined according to distinct cytomorphologic characteristics, without knowledge of the lesion of origin. The 3 individual scorers, 2 cytopathologists and 1 senior cytotechnologist, most frequently agreed upon the cells classified as "moderate dysplasia." The measurements of digitized cells in this category had the smallest confidence intervals of any of the abnormal cell categories. For these 2 reasons, as well as the ubiquitous nature of "moderate dysplasia" cells in smears obtained from all patients with cervical epithelial neoplasia, cells in this category were studied in greater detail. Significant differences were noted in cell measurements among cells in this class when the cells came from patients with different grades of cervical neoplasia. Visually similar "moderate dysplasia" cells can be separated by digitized measurements into clusters dependent upon the parent lesion. The biologic implications are not yet clear, but each disease is perhaps a committed lesion from inception. Predictability of ultimate outcome could be based on image analysis of cells derived from early cervical lesions, which would allow therapy to be performed on a more logical basis.