Upgrade Rates of Pure, Radiology-Pathology Concordant Lobular Neoplasia Diagnosed on Breast Core Needle Biopsy: Is Surgical Excision Warranted?

ABSTRACT

OBJECTIVE: To determine upgrade rates of lobular neoplasia (LN) to malignancy and evaluate factors that may predict upgrade. METHODS: From 5/1/2003 to 12/30/2015, breast lesions diagnosed as LN (atypical lobular hyperplasia [ALH] or classic lobular carcinoma in-situ [LCIS]) on core biopsy that underwent surgical excision or at least 2 years imaging follow-up were identified. A subspecialty trained breast radiologist and pathologist reviewed imaging and pathology slides to confirm diagnosis and to determine if LN represented the target lesion, part of the target lesion, or an incidental finding. Imaging features, original BI-RADS final assessment category, biopsy method, biopsy device and final pathologic diagnosis were documented. Cases with both ALH and LCIS were classified as LCIS for analysis. Reason for biopsy of BI-RADS 2-3 was patient or referring physician preference. Upgrade rates to malignancy were determined for all cases. RESULTS: In this study 73.7% (115/156) lesions were ALH and 26.3% (41/156) were LCIS+/-ALH. Surgical excision and imaging follow-up were performed in 71.2% (111/156) and 28.8% (45/156), respectively. Upgrade rates for ALH and LCIS were 0.0% (0/115) and 7.3% (3/41), respectively. Cancer developed at a site separate from core biopsy in 1.7% (2/115) ALH and 7.3% (3/41) LCIS cases. We found no association of upgrade rate with biopsy type, BI-RADS or target/part of target lesion versus incidental. CONCLUSION: Our study supports consideration of excision for LCIS, given 7.3% upgrade rate. Conversely, imaging surveillance might be appropriate following diagnosis of ALH alone.