The aims of this study were: (a) to assess p53 nuclear accumulation and ERα expression in pure ductal hyperplasia and ductal hyperplasia co-existing with DCIS or IDC; (b) to explore if there is a differential expression pattern of ERα and p53 nuclear accumulation between pure ductal hyperplasia and ductal hyperplasia co-existing with DCIS or IDC. Here, ESR1 is linked to ductal breast carcinoma in situ.