Probably benign lesions at breast magnetic resonance imaging

Open Access
Publisher Website
Google Scholar
Abstract
BACKGROUND The purpose of the current study was to determine the frequency of ‘probably benign’ interpretations at breast magnetic resonance (MR) imaging screening of high-risk women and the frequency of subsequent malignancy in these women. METHODS The authors performed a retrospective review of the records of 367 asymptomatic women with normal mammograms who had a high risk of developing breast cancer and whose first breast MR imaging screening examinations occurred during a 2-year period. The number of “probably benign” interpretations was determined, and follow-up data were obtained. RESULTS A “probably benign” interpretation was given to 89 (24%) of 367 women. Follow-up MR imaging was performed for 70 (79%) of 89 women, with a median follow-up time of 11 months (range, 1–24 months). Twenty women subsequently underwent biopsy at a median of 9 months (range, 1–18 months) after MR imaging, due to progression on follow-up MR imaging (n = 14) or for other reasons (n = 6). Malignancies were found in 9 women, constituting 45% of the 20 women who underwent biopsy and 10% of the 89 women with probably benign lesions. In 6 of the 9 women who developed malignant disease (7% of the 89 women in the study), the malignancy was detected by follow-up MR imaging of an area that previously was interpreted as probably benign. Tumor histology was ductal carcinoma in situ (DCIS) in five patients and infiltrating ductal carcinoma in four. CONCLUSIONS A “probably benign” interpretation was given to 24% of high-risk women at their first breast MR imaging screening examination. In 7–10% of women with “probably benign” interpretations, malignant disease subsequently developed in an area initially judged to be probably benign; of these malignancies, more than half were DCIS, and more than half were detected by MR imaging only. Cancer 2003;98:377–88. © 2003 American Cancer Society. DOI 10.1002/cncr.11491