E73: Radial Scar Upgrade Rate After Excisional Biopsy

Radial scars (RS) are classically small spiculated lesions causing distortion on mammography which can mimic carcinoma. They have been associated with an up to 40% risk of upgrade to carcinoma on excisional biopsy; however, more recent data suggest that with vacuum assisted core needle biopsy (CNB) and confirmation of radiologic-pathologic concordance, the upgrade rate may be significantly lower, questioning the utility of routine excisional biopsy for a radiologic-pathologic concordant finding of RS.

Methods:

Patients with radiologic-pathologic concordant RS without atypia on CNB were identified from a single institution database and rate of upgrade to carcinoma after excisional biopsy and clinicopathologic features were assessed via retrospective chart review.

Results:

A total of 184 patients with 197 core needle biopsies for RS without atypia were evaluated. Average age was 55 years. Patient ethnicity was 62% White, 16% Asian, 9% Black, 3% Hispanic, and 10% from other ethnicities.  Excisional biopsy was performed in 71% (n=140) of cases. Overall upgrade rate of RS to invasive carcinoma on excisional biopsy was 0% (n=0). Upgrade rate to DCIS was 0.7% (n=1). Upgrade to LCIS was 1.4% (n=2).  Biopsy site changes without residual RS were found in 21% (n=30) of cases on excisional biopsy. Only 11% (n=16) of patients with RS alone on CNB were found to have atypia without carcinoma on excisional biopsy.  

Conclusions:

Upgrade rate to carcinoma after excisional biopsy for radial scar without atypia on CNB was 0.7%. This is much lower than historically described rates in prior literature and parallels more recent reports. Additional study is warranted to identify which patients with RS on CNB benefit from excisional biopsy.