Background: When needle core biopsies (NCBs) of the breast reveal radial scar or complex sclerosing lesions (RSLs), excision is often recommended despite a low risk of malignancy in the modern era. The optimal management of NCBs revealing RSLs is controversial, and understanding of the natural history of unresected RSLs is limited.
Methods: We retrospectively analyzed pathology and imaging data from 148 patients with NCB revealing RSL without atypia from 2015 to 2019 to determine the prevalence of malignancy and the behavior of RSLs undergoing active surveillance (AS).
Results: The mean age of patients was 52 years, and most lesions were screen-detected (91%). The median lesion size was 6.0 mm (range 2-39). Most patients (66%, n = 98) underwent immediate surgery, while 34% (n = 50) of patients underwent AS, with a median follow-up of 16 months (range 6-51). Of the excised RSLs, 99% (n = 97) were benign and 1% (n = 1) revealed ductal carcinoma in situ (DCIS). In 17% (n = 17) of cases, additional high-risk lesions were discovered upon excision. Among the 50 patients undergoing AS, no lesions progressed on interval imaging.
Conclusions: In this cohort, 99% of RSLs undergoing excision were benign, 1% revealed DCIS, and there were no invasive cancers. In the first study of patients with RSLs undergoing AS, we found that all lesions either remained stable or resolved. We propose that the vast majority of patients with RSL on NCB can be safely offered AS, and that routine excision is a low-value intervention.
© 2021. Society of Surgical Oncology.