Reducing indications for radial scar surgical excision in Slovenian breast cancer screening program

Management of the radial scar (RS)/complex sclerosing lesion (CSL) diagnosed by core needle biopsy (CNB) in breast cancer screening population (BCSP) is controversial due to its intrinsic malignant potential. We aimed to determine (i) the rate of upgrade of the RS/CSL to malignant lesions and (ii) radiological characteristics and CNB histopathological findings of the lesions related to the upgrade of the RS/CSL to malignant lesions after surgical excision in our BCSP.

Database of Slovenian National Breast Cancer Screening Program was checked for terms RS/CSL in all patients who underwent CNB in the period 2008-2018. The ratios of upgrade from CNB RS/SCL to malignant lesions after surgical excision were calculated with specific interest to the radiological characteristics and the CNB patohistologically findings of the lesions.

Of 162 patients with diagnosis of RS/CSL on the CNB, 121/156 (78%) cases underwent surgical excision. 6 of 121 (5%) cases were upgraded to a malignant diagnosis in surgical specimen, 3 cases of invasive carcinoma and 3 cases of DCIS, respectively. Five of the upgraded cases (5/6, 83.3%) showed atypical epithelial proliferative lesions (AEPL) on CNB. In one upgraded case without AEPL the lesion presented as 33 mm architectural distortion with microcalcifications on the mammogram.

In BCSP setting RS/CSL without AEPL/papilloma and those measuring less than 2 cm in the largest diameter can be followed radiologically. Increasing the number of cores and adequate sampling of the periphery and the centre of the RS/CSL improves the pick-up rate of associated atypia/malignancy.