Cervical intraepithelial neoplasia: false negative smears

In the early days of cervical cytology there was a general assumption that mistakes would be a rare occurrence. These expectations were unrealistic given the fatiguing nature of the work and its dependence on human judgement. Media attention and the introduction of quality control have highlighted inadequacies in the service. The reasons for both sampling and screening errors which give rise to the issuing of false negative smear results need to be understood before measures can be taken to minimise them. An acceptable error rate should be recognised and, if possible, improved upon. Further investigations into the role of human papilloma virus (HPV) in the development of cervical cancer, and evaluation of automated screening, should lead to improvements in the cervical screening programme.