A clinically detectable, frankly invasive, squamous cell carcinoma of the uterine cervix evolves through a series of step-like stages, at any one of which, except the last, its progress can be arrested. These stages are intraepithelial neoplasia, early stromal invasion, microcarcinoma and, eventually and irreversibly, invasive squamous cell carcinoma. Crucial to this concept of a series of plateaus in tumour development is the recognition that "dysplasia" is a differentiated intraepithelial neoplasm and the discarding of the term "cancer" in favour of the less emotionally loaded expression "neoplastic process".