The Bethesda system and evaluation of abnormal pap smears

The Bethesda Pap Smear system and its 1991 revisions aim to simplify Papani colaou (Pap) smear reporting and make it more reproducible. It redefines th e Pap smear request as a medical consultation. The pathologist consultant i s required not only to provide the smear reading but also its clinical reco mmendation. The Bethesda system insists on a detailed Pap smear report asse ssing specimen adequacy and types of epithelial changes. Squamous cell abno rmalities are grouped according to their biologic potential. Both cervical intraepithelial neoplasia, grade I (CIN I) (mild dysplasia) and human papil lomavirus (HPV) lesions are grouped together as low-grade squamous intraepi thelial lesions (LGSIL), while moderate and severe dysplasia (CIN II and II I) belong to the high-grade squamous intraepithelial lesion (HGSIL) categor y. Atypical squamous cells of undetermined significance (ASCUS) and atypica l glandular cells of undetermined significance (AGCUS) need further qualifi cation as to whether they favor either a reactive or neoplastic process. Gu idelines for management of abnormal Pap smears are discussed in detail. Sem in. Surg. Oncol. 16:217-221, 1999. (C) 1999 Wiley-Liss, Inc.