Classic lobular carcinoma in situ and atypical lobular hyperplasia at percutaneous breast core biopsy: outcomes of prospective excision

Abstract

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, vacuum-assisted 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.