Sonographic Findings of Additional Malignant Lesions in Breast Carcinoma Seen by Second Look Ultrasound

OBJECTIVE: The aim is to show ultrasound (US) findings of additional malignant lesions of breast carcinoma visualized on targeted second-look US that were not identified by mammography or US prior to the time of diagnosis. MATERIALS AND METHODS: A double-blind retrospective review of the US results from January 2008 through August 2010 of 228 patients with known breast cancer was conducted by two expert radiologists. The focus of the review was on the second-look US characteristics (following BI-RADS criteria) of 26 documented additional malignant lesions of the 76 with successful sonographic correlation from the 123 lesions detected by magnetic resonance imaging (MRI). All of them, before the MRI, had an initial mammography and a US with a histopathological biopsy of the primary lesion. RESULTS: Approximately 60 to 70% of the findings were classified as BI-RADS 2 and BI-RADS 3, while assessing the final US category. The review of the second-look US showed the size of the second malignant additional lesion ranged from 3 to 22 mm, of which 90% were smaller than 10 mm and 66% were smaller than 7 mm. CONCLUSIONS: Most additional malignant lesions, nonpalpable carcinomas, which were previously not detected by mammography and US at first-look diagnosis, were detected by a targeted second-look US examination. These lesions were of category BI-RADS 2 and BI-RADS 3 and smaller than 7 mm.