Flat epithelial atypia and the risk of sampling error: Determining the value of excision after image-guided core-needle biopsy

Abstract Background We determined the sampling error rate of flat epithelial atypia (FEA) and evaluated current guidelines recommending excisional biopsy. Methods A retrospective review of consecutive excisional biopsies after image-guided core-needle biopsy identified patients with isolated FEA diagnosed between 2014 and 2018. Clinical and pathologic parameters were evaluated. Results Twenty-five women with 27 biopsies were included. Based on pathologic review of original core specimens, 44.4% (N=12) were accurately diagnosed as FEA. Upon excision, lesions were upgraded to ductal carcinoma in situ (N=2) or invasive ductal carcinoma (N=1) in 11.1% of cases. Older age, black race, hormone replacement, and calcifications in the image-guided biopsy specimen were associated with the presence of high-risk or malignant lesions in the excisional biopsy (all p ≤0.05). Conclusions In this study, FEA was frequently overcalled. However, lesions suspicious for FEA warrant excision due to their association with malignancy or high-risk lesions, which may necessitate further surgical management and/or risk-reducing strategies.