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).
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.
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).
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.