Radial Scars Without Atypia Diagnosed at Percutaneous Core Needle Breast Biopsy: Support for Imaging Surveillance.

Objective: Radial scar (RS) is a low-risk breast lesion that can be associated with or mimic malignancy. Management guidelines remain controversial for patients with RS without atypia on core needle biopsy (CNB). The aim was to evaluate the upgrade rate of these lesions and factors associated with malignancy risk and excision rate to more definitively guide management.

Materials and methods: In this retrospective study, 123 patients with RS without atypia, diagnosed with CNB between January 2008 to December 2014 who were either referred for surgical excision or followed-up with imaging, were reviewed. The differences in clinical presentation, imaging features, and biopsy technique among the benign RS patients and those upgraded, as well as the excised versus the observed patients were compared.

Results: Of 123 RS reviewed, 93 cases of RS without atypia as the highest-grade lesion in the ipsilateral breast and with either 24-month imaging follow-up or surgical correlation were included. Seventy-four (79.6%) lesions were surgically excised and 19 (20.4%) were followed-up for at least 24 months. A single upgrade to malignancy (1%) and 15 upgrades to high-risk lesions (16%) were found. There was no association of any upgraded lesion with presenting symptoms or imaging features. The use of vacuum-assistance and larger biopsy needles, along with obtaining a higher number of samples, was associated with fewer upgrades and lower surgical excision rates.

Conclusion: The upgrade rate of RS without atypia in our population was low, regardless of the imaging features and biopsy technique utilized. Close imaging surveillance is an acceptable alternative to surgical excision in these patients.