Radial sclerosing lesions of the breast: mammographic and pathologic correlation

The purpose of this study was to define the mammographic appearance of 96 pathologically proven radial sclerosing lesions (RSLs) and to determine the frequency of association with malignancy in and around the lesions.

Ninety-three patients with 96 RSLs were identified from the pathology files of the BC Cancer Agency, and the reasons for biopsy were obtained. All preoperative mammograms were reviewed, and the RSLs were categorized as classic (typical), non-classic (atypical), or incidental. The histopathologic results were retrospectively examined for atypia, ductal carcinoma in situ (DCIS) and invasive carcinoma.

In 67 of the 96 biopsies, the RSL was the primary mammographic abnormality that led to biopsy. In this group, 17 cases (25.4%) contained atypia, 17 (25.4%) DCIS, and 4 (6%) invasive carcinoma. Nineteen of these RSLs presented as mass-like opacities that mimicked carcinoma. No single mammographic feature consistently predicted premalignant or malignant lesions. In the remaining 29 patients, biopsy was carried out because of pleomorphic calcifications or masses, and RSLs were found incidentally in specimens. These specimens included 4 cases (13.8%) of atypia, and 1 case (3.4%) of DCIS.

Of the 67 mammographically detected RSLs, only 48 (71.6%) had a typical mammographic appearance. We found a significant amount of atypia (25.4%) and malignancy (25.4% DCIS and 6% invasive carcinoma) in mammographically detected RSLs. Because of the lack of predictable radiological features, adequate open surgical biopsy is recommended for all focal abnormalities in which a RSL is a possible diagnosis.