Management of papillary lesions of the breast: can larger core needle biopsy samples identify patients who may avoid surgical excision?

Background: The ability to distinguish benign from atypical/malignant papillary lesions on core needle biopsy is limited by the representative nature of the biopsy method, thus follow-up excision is usually recommended. We aimed to determine if larger samples of tissue obtained by core needle biopsy can more reliably predict the true benign nature of a papilloma.

Methods: We reviewed the pathology slides and medical records of 51 patients who were diagnosed with benign papillomas on core needle biopsy from 2000 to 2010, who subsequently underwent surgical excision. The characteristics of the core needle biopsy that were associated with retention of benign histology on excision were determined and analyzed.

Results: Atypical ductal hyperplasia and carcinoma were identified in 5.8 % (3/51) and 5.8 % (3/51) of papillary lesions, respectively, when excised. Patients whose lesions were diagnosed as benign on excision were significantly distinguished by the area (mm(2)) of tissue sampled by core needle biopsy (mean ± standard deviation (SD): 101.5 ± 106.5) compared with those with atypia or carcinoma on excision (mean ± SD: 41.7 ± 24.0, P = 0.003). All biopsies performed with 12-gauge or larger needles retained benign features on excision. Core needle biopsy tissue samples consisting of ≥7 cores, or measuring >96 mm(2) in aggregate, had a negative predictive value for atypia/malignancy of 100 %.

Conclusions: Larger tissue samples significantly improved the predictive value of benign histology on core needle biopsy. A papilloma sampled by a 12-gauge or larger needle, ≥7 cores, or >96 mm(2) retained its benign features upon excision.