Radial sclerosing lesions diagnosed by percutaneous breast biopsy: histologic upgrade rate and management implications

Introduction: Management of benign radial sclerosing lesions (RSLs) remains controversial, with no consensus on surgical excision. The aims of this study were to compare the rate of histologic underestimation of high-risk lesions or carcinomas associated with benign RSLs based on breast biopsy method and to determine the upgrade of RSLs after surgical excision, when performed, or during imaging follow-up. Material and methods: This retrospective cohort study analyzed RSLs in women who underwent percutaneous breast biopsy followed by surgical excision or at least 24 months of imaging surveillance. RSLs were detected by mammography, ultrasound (US) and/or magnetic resonance imaging (MRI) and were confirmed histopathologically. Diagnostic methods included percutaneous ultrasound core needle biopsy (US-CNB), ultrasound vacuum-assisted biopsy (US-VAB), stereotactic vacuum-assisted biopsy (VAB) and/or surgical excision. Histologic diagnoses were benign RSLs, RSLs with high-risk lesions or breast cancer associated. Results: Ninety-seven women with 97 RSLs were included — 75 with US-CNB and 22 with VAB. The upgrade rate varied by biopsy method. With US-CNB, 8 (10.7%) lesions were upgraded to high-risk lesions after surgical excision and one (1.3%) was upgraded to carcinoma in situ (CIS). Another case (1.3%) had a percutaneous diagnosis of high-risk RSL was upgraded to microinvasive cancer. There were no upgrades to high-risk lesions or cancer in 12 US-VAB cases. All remained stable during follow-up (n = 10, 83.3%) or were confirmed benign surgically (n = 2, 16.7%). Of the 10 RSLs sampled with stereotactic VAB, one (10.0%) was upgraded to a high-risk lesion. Conclusion: In our study, US-VAB demonstrated no histologic underestimation of malignancy compared with US-CNB or stereotactic VAB. Given this low risk, semiannual imaging for two years is a safe alternative to surgical excision in patients with RSLs diagnosed on percutaneous biopsy.