BACKGROUND:No consensus exists on the need to excise breast lesions that yield classic lobular carcinoma in situ (LCIS) or atypical lobular hyperplasia (ALH) (known together as classic lobular neoplasia [LN]) as the highest risk lesion at percutaneous core-needle biopsy (CNB). Here, the authors report findings from 72 consecutive lesions with LN at CNB and prospective surgical excision (EXB). METHODS: Lesions that yielded LN at CNB at the authors' center have been referred for EXB since June 2004, regardless of imaging-histologic concordance. A lesion was ''concordant'' if histologic findings provided sufficient explanation for imaging. An upgrade consisted of ductal carcinoma in situ and/or invasive carcinoma at EXB. Statistical analysis, including 95% confidence intervals (CIs), was performed. RESULTS: Between June 2004 and May 2009, CNB of 85 consecutive lesions yielded LN without other high-risk histologies. Eighty of 85 lesions (94%) underwent prospective EXB. Seventy-two of 85 lesions (90%; 42 LCIS, 30 ALH) had concordant imaging-histologic findings. EXB yielded low-grade carcinoma in 2 of 72 cases (3%; 95% CI, 0%-9%). In both patients, stereotactic, 11-gauge, vacuumassisted biopsy of calcifications yielded calcifications in benign parenchyma and ALH. CNB results were discordant in 8 of 80 lesions (10%; 4 LCIS, 4 ALH), and EXB yielded cancer in 3 of those 8 lesions (38%; 95% CI, 9%-76%). The upgrade rate was significantly higher for discordant lesions versus concordant lesions (38% vs 3%; P <.01). CONCLUSIONS: Prospective excision of LN identified carcinoma in 3% (95% CI, 0%-9%) of concordant cases versus 38% (95% CI, 9%-76%) of discordant cases. The current data provide an unbiased assessment of the upgrade rate of LN diagnosed at CNB. Cancer 2013;119:1073-9. V C 2012 American Cancer Society.KEYWORDS: lobular neoplasia, core biopsy, breast, concordance, upgrade rate.
INTRODUCTION
Classic lobular neoplasia (LN) of the breast includes atypical lobular hyperplasia (ALH) and lobular carcinoma in situ with classic morphology (LCIS).Recently recognized lobular proliferations with unusual morphologic features, such as pleomorphic LCIS and LCIS with massive acinar distention, necrosis, and coarse calcifications are not part of classic LN. 1 LN is associated with a high risk of subsequent invasive carcinoma in either breast, with higher risk for LCIS 2 than for ALH. 3 Although recent data indicate that LCIS represents a nonobligate precursor of invasive lobular carcinoma, 4 LN continues to be managed clinically as a high-risk lesion. 5 In theory, the presence of LN in tissue obtained at core-needle biopsy (CNB) could represent an incidental finding. It is possible to hypothesize that surgical excision is only warranted if the pathologic findings do not account for the imaging target. Currently, however, there is an open debate on the need to excise a breast target that yields LN as the highest risk lesion at CNB, because some series report significant rates of upgrade. [6][7][8][9] Most studies addressing this iss...