A critical appraisal of existing classification systems of epithelial hyperplasia and in situ neoplasia of the breast with proposals for future methods of categorization: Where are we going?

Current classification systems for borderline lesions of the breast includi ng epithelial hyperplasia, atypical hyperplasia, and ductal carcinoma in si tu fall short of the ideal. They present pathologists with problems of reco gnition or clear distinction and clinicians with difficult management choic es. In addition, recent evidence indicates that different pathogenetic lesi ons are present in some categories. This article presents a brief critical appraisal of the existing classifications and offers suggestions for revisi on using a model of pathogenetic lineage. Copyright (C) 1999 by W.B. Saunde rs Company.