The Predictive Value of Second-Look Ultrasound after Preoperative Breast Magnetic Resonance Imaging

Abstract

Purpose: The purpose of the current study was to evaluate the usefulness of second-look ultrasonography (US) for evaluating incidental enhancing lesions identified on preoperative breast magnetic resonance imaging (MRI) performed to stage malignant lesions. Methods: We studied 88 patients with suspected breast malignancy on conventional mammography and/or whole-breast US and invasive carcinoma subsequently confirmed by cytology or core biopsy, who underwent preoperative breast MRI for accurate breast cancer staging between January 2011 and July 2014. Patients’ demographic, clinical and pathological characteristics were assessed. Results: Seven hundred fortynine patients underwent preoperative breast MRI, and the imaging detected incidental enhancing lesions in 257 patients. Second-look US was performed to evaluate 126 incidental enhancing lesions in 88 patients. We evaluated the frequency of malignancy as a function of lesion size on MRI, lesion size on second-look US, menstrual status, and age. The frequency of malignancy was higher for lesions 0.6 cm or larger on MRI than for smaller lesions (25.9% vs. 0%), and this difference was statistically significant (p=0.032). Conclusion: In conclusion, we found that the frequency of malignancy increased with the size of incidental enhancing lesions detected by MRI. On the basis of our results, biopsy is warranted in cases of incidental enhancing lesions 0.6 cm or larger on MRI. Further study with a larger series of cases and including more detailed subgroup analyses is necessary to develop reliable management guidelines for these lesions.