Cervical cytology classification and the Bethesda System

Cervical cancer screening represents one of the great success stories in cancer prevention. Cervical cytology results were reported by use of various terminologies during the first 40 years of widespread screening. These terms did not correspond to current knowledge of cervical carcinogenesis. The Bethesda System for reporting cervical cytology was developed to provide a uniform system of terminology that would promote clear management guidelines. The Bethesda System has been widely adopted since the first workshop was convened by the National Cancer Institute in 1988. Two additional workshops were held in 1991 and 2001 in order to address scientific advances and controversial areas. The 2001 workshop was attended by more than 400 participants and was preceded by Internet discussion groups. Major changes include specimen adequacy designation and criteria, general categorization, and terminology for atypical epithelial cells. The "within normal limits" and "benign cellular changes" categories have been combined into a single category called "negative for intraepithelial lesion or malignancy." The "favor reactive" descriptors have been removed from the atypical epithelial categories, and new terms correlate better with management guidelines. Other changes are discussed, and a brief update of cancer screening guidelines is also provided.