Papillary lesions of the breast at percutaneous core-needle biopsy

PURPOSE: To retrospectively review the imaging and histologic findings in patients in whom a benign papillary lesion was diagnosed at core-needle breast biopsy. MATERIALS AND METHODS: This retrospective study was approved by the institutional review board at each institution; patient consent was not required. The study was HIPAA compliant. The authors reviewed the findings from 42 patients (age range, 26-76 years; mean age, 54.3 years) with 43 benign papillary lesions diagnosed at core-needle biopsy. Thirty-six (84%) of the 43 lesions were surgically excised, and seven (16%) were followed up with long-term imaging. The authors assessed the radiographic findings, the histologic findings at core-needle biopsy, and the findings at subsequent surgical excision or imaging follow-up. Statistical analysis was performed on a per-patient basis and included the Blyth-Still-Casella procedure to construct exact 95% confidence intervals (CIs) and the Fisher exact test. RESULTS: At core-needle biopsy, lesions were diagnosed as papilloma (n = 29), sclerosing papilloma (n = 8), and benign papillary lesions not otherwise specified (n = 6). For the 36 lesions that were surgically excised, histologic follow-up showed no residual lesion in 10, intraductal papilloma in 14, intraductal papillomatosis in two, papilloma with adjacent foci of atypical ductal hyperplasia (ADH) in eight, and well-differentiated papillary ductal carcinoma in situ (DCIS) in two. Mammographic follow-up in the remaining seven lesions revealed stable calcifications in five (at 28-55 months) and no residual lesion in two (at 26-29 months). In nine of the 42 patients (21%), the diagnosis was upgraded to either ADH or DCIS (exact two-sided 95% CI = 11.4%, 36.4%). CONCLUSION: The results strongly suggest that papillary lesions diagnosed as benign at core-needle biopsy should be surgically excised because a substantial number of lesions were upgraded to ADH and DCIS at excision.