To compare the outcomes of US-guided 14-gauge automated biopsy and 11-gauge vacuum-assisted biopsy for the papillary lesions of the breast.

We retrospectively reviewed the US-guided core biopsies of 1,723 consecutive breast lesions that were treated from January 2003 to April 2005. Ninety-eight lesions (5.7%) were pathologically reported as papillary lesions. The biopsies were performed with using a 14-gauge automated gun on 65 lesions or with using an 11-gauge vacuum-assisted device on 33 lesions. Thirty-five lesions (54%, 35/65) of 14-gauge automated gun biopsies and 5 lesions (15%, 5/33) of 11-gauge vacuum-assisted biopsies underwent surgery. The histologic findings were compared with the surgical, imaging and follow-up findings. The histologic underestimation rate, the repeat biopsy rate and the false negative rate were compared between the two groups. The repeat biopsy rate was determined by dividing the total number of core biopsies into the number of repeat biopsies. "ADH underestimation" was defined as a lesion yielding atypical ductal hyperplasia on percutaneous biopsy and carcinoma at surgery, and "DCIS underestimation" was defined as a lesion yielding ductal carcinoma in situ on percutaneous biopsy and invasive carcinoma at surgery.

The repeat biopsy rate was 42% (27/65) for the 14-gauge automated gun biopsies and 9.1% (3/33) for the 11-gauge vacuum-assisted biopsies. The ADH underestimation rate was 50% (7/14) for the 14-gauge automated gun biopsies and 0% (0/4) for the 11-gauge vacuum-assisted biopsies. The DCIS underestimation was 14% (1/7) for the 14-gauge automated gun biopsies and 0% (0/2) for the 11-gauge vacuum-assisted biopsies. The false negative rate was 0% for these two groups.

For the papillary lesions of the breast, the outcomes of the US-guided core biopsies performed with the 11-gauge vacuum-assisted device were better than those of the biopsies performed with the 14-gauge automated gun, in terms of underestimation and repeat biopsy.