Ductal carcinoma in situ: diagnosis and classification

Abstract

Ductal carcinoma in situ (DCIS) is an intraepithelial proliferation with features of malignancy, localized predominantly within ducts and believed to derive from the terminal duct-lobular units. The UK National Health Breast Screening Programme currently recommends a nuclear-based grading system that appears to correlate with biological markers. Increasingly, genetic data are identifying consistent differences between low- and high-grade DCIS, and also suggest that in situ recurrences are, in fact, residual disease rather than a de novo new in situ carcinoma.