How Do We Approach Benign Proliferative Lesions?

Abstract

The aim of this review is to summarize recently published literature addressing atypical ductal hyperplasia (ADH), lobular neoplasia (atypical lobular hyperplasia [ALH] and classic lobular carcinoma in situ [C-LCIS]), non-classic lobular carcinoma in situ (NC-LCIS), papillary lesions, and flat epithelial atypia (FEA). While ADH, ALN, and C-LCIS are well-established markers of an increased risk of future breast cancers, the risk implications are less clear for papillary lesions and FEA. NC-LCIS is the least well-characterized lesion, with scant published literature on its natural history and surgical management when encountered on needle biopsy. Recent data suggest that lobular neoplasia on core biopsy of a BI-RADS ≤ 4 concordant lesion does not require an excision, while ADH, atypical papillomas, and NC-LCIS should be excised. Evidence on FEA and papillomas without atypia suggests a low risk of upgrade on excision, and prospective studies on the upgrade of these lesions are ongoing.