Imaging-guided core needle biopsy of papillary lesions of the breast.

OBJECTIVE: Our objective was to assess the incidence of papillary lesions of the breast diagnosed at imaging-guided core needle biopsy and the need for surgical excision after a benign diagnosis.

MATERIALS AND METHODS: This retrospective study included 1374 patients with consecutive suspicious breast lesions that underwent either mammography or sonographically guided large-core needle breast biopsy. Fifty-seven lesions (4%) were classified as papillary lesions. Eleven of the 57 cases were lost to follow-up (n = 6) or had not yet shown 2 years of stability (n = 5) and were excluded from this study. The remaining 46 papillary lesions constitute our study population.

RESULTS: Surgical excision was performed in 17 (37%) of 46 papillary lesions. In the group of patients whose lesions were recommended for excision because carcinoma was identified at core biopsy, surgical excision revealed one false-positive and two true-positive diagnoses. In four cases, histologic diagnoses of the excisional biopsy and the core needle biopsy were discordant. One false-positive finding at core needle biopsy initially was interpreted as invasive ductal carcinoma on the basis of core needle biopsy specimens. In three false-negative findings, the initial diagnosis at core needle biopsy was upgraded after surgical excision. Two cases of papilloma with adjacent atypical ductal hyperplasia and one of atypical papilloma were upgraded to ductal carcinoma in situ after surgical excision. Imaging follow-up was performed in the remaining 29 patients. All lesions were stable or had decreased in size during the 2-year follow-up period. The negative predictive value of core needle biopsy for excluding malignancy among the papillary lesions diagnosed in our study was 93%.

CONCLUSION: When the histologic diagnosis is benign, our data suggest that papillary lesions may be safely managed with imaging follow-up rather than with surgical excision. However, atypical papillary lesions or those associated with atypia require surgical excision because histologic underestimation occurs at a frequency similar to that in other atypical lesions undergoing core needle biopsy.