Molecular Distinction Between Atypical Ductal Hyperplasia and Ductal Carcinoma In Situ

Abstract: The increasing use of screening mammography has led to an increased detection of high-risk proliferative breast disease and premalignant breast lesions. This change in the pattern of disease presentation has highlighted the existing limitations in the understanding of the biology of these entities. It has also emphasized the significance of deficiencies involved in the morphologic recognition of the spectrum of changes that occur in precursor lesions. The criteria for morphologic distinction between atypical ductal hyperplasia (ADH) and low-grade ductal carcinoma in situ (DCIS) have remained controversial. There are also difficulties in subclassification of DCIS. To resolve some of these issues, attempts have been made to use new and emerging technologies to study these borderline breast lesions and to distinguish between ADH and DCIS. This article discusses the significance of the newly recognized biomarkers and emphasizes the need for further prospective studies.