How Do We Approach Benign Proliferative Lesions?

Area of Science:

• Breast pathology
• Oncology
• Dermatology

Background:

• 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) are important breast lesions.
• ADH, ALN, and C-LCIS are established markers for increased breast cancer risk.
• The risk implications for papillary lesions and FEA are less clear, and NC-LCIS is the least well-characterized.

Purpose of the Study:

• To summarize recent literature on ADH, lobular neoplasia (ALH, C-LCIS, NC-LCIS), papillary lesions, and FEA.
• To clarify the risk implications and management of these breast lesions.
• To review the natural history and surgical management of NC-LCIS.

Main Methods:

• Literature review of recently published studies.
• Synthesis of data on risk stratification and management guidelines.
• Analysis of evidence regarding upgrade rates on excision.

Main Results:

• Lobular neoplasia on core biopsy of a BI-RADS ≤4 concordant lesion does not require excision.
• ADH, atypical papillomas, and NC-LCIS should be excised.
• FEA and papillomas without atypia have a low risk of upgrade on excision, with ongoing studies.

Conclusions:

• Management strategies for ADH, lobular neoplasia, papillary lesions, and FEA are evolving.
• Excision is recommended for ADH, atypical papillomas, and NC-LCIS.
• Further prospective studies are needed to confirm the low upgrade risk for FEA and papillomas without atypia.