Abstract P1-02-08: Papillary lesions of the breast on core biopsies: Should routine surgical excision be performed?

Abstract

Abstract Background: The optimal management of papillary lesions, particularly benign papillomas, detected on core needle biopsies remains debatable. The purpose of this study was to determine the risk of upgrade to malignancy of core biopsy diagnosed papillary lesions on the subsequent surgical excision. Methods: Following institutional ethics review board approval, the pathology database was searched for all papillary lesions diagnosed on core needle biopsies from Jun 2005 to June 2010. The papillary lesions were histologically categorized as benign, atypical, suspicious for malignancy and definite for malignancy. The core biopsy findings were compared with the follow-up excision biopsy material to identify any upgrade to malignancy (i.e. ductal carcinoma in situ or invasive carcinoma). The presence of any associated significant risk lesions such as atypical ductal hyperplasia (ADH) and lobular neoplasia (LN) were also recorded. Results: A total of 113 papillary lesions were diagnosed on core needle biopsies of 98 patients, with a mean age of 57 years. A median of 5 cores of breast tissue were obtained per papillary lesion. Of these papillary lesions, 73 were benign, 25 atypical, 8 suspicious for malignancy and 7 definite for malignancy. The overall excision rate was 83%. Of the 58 benign papillary lesions excised, only one (1.7%) showed malignancy (3mm ductal carcinoma in situ) - of interest, the papillary lesion per se was confirmed benign on excision, while an adjacent focus of flat epithelial atypia was present in the initial core biopsy. Nine papillomas were associated with adjacent ADH and/or LN on excision and the rest of the excisions (n = 48) showed no residual papillary lesion or benign papillomas. Among the 24 excised atypical papillary lesions, the positive predictive value (PPV) for malignancy was 42% (10 in situ papillary carcinomas, 4 of these associated with invasive carcinoma). The remaining excisions disclosed ADH and/or LN (n = 3) or benign breast tissue/papillomas (n = 11). None of the 4 papillary lesions with the apocrine atypia were malignant on excision. Of the 5 excised papillary lesions which were suspicious for malignancy on the cores, all showed malignancy (5 in situ carcinomas; 2 associated with invasive carcinoma) on open surgical biopsy. The PPV for malignancy of the 7 core biopsy diagnosed malignant papillary lesions was 100%. Conclusions: Papillary lesions diagnosed as atypical or suspicious for malignancy on core needle biopsies should be completely excised to exclude malignancy. Our findings suggest, however, that routine surgical excision may not be necessary for core biopsy detected benign papillomas which are not associated with atypia. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-02-08.