Probably Benign Breast Nodular Lesions (BI-RADS 3): Correlation between Ultrasound Features and Histologic Findings.

The purpose of this retrospective study was to determine the validity of the BI-RADS system in ultrasound findings assigned to BI-RADS 3 category, using cytologic and histologic results as a benchmark. Our study population consisted of 122 ultrasound nodular lesions in 122 women who underwent fine-needle aspiration cytology and biopsy for probably benign lesions (Breast Imaging Reporting and Data System [BI-RADS] category 3). Contrary to what was previously reported in the literature (risk of malignancy of BI-RADS 3 <2%), malignancy was the outcome in seven of 122 cases (5.7%). Our study also found that the presence of a cellular component with a mobile fluid-fluid level in a cystic lesion and small (<3 mm) anechoic components in solid lesions is not always an indication of benignity. Our experience seems to indicate the need to consider the presence of non-homogeneous echoes in the corpuscular cyst and solid nodular lesions with cystic components as suspicious, especially in lesions with large dimensions. Therefore it would be necessary to conduct further studies to establish a dimensional criterion in the assessment of the malignant nature of the mentioned lesions. The management of probably benign nodular lesions should not only be guided by BI-RADS classification; it is also necessary to include clinical and anamnestic data and apply a multidisciplinary approach to select cases that require histologic verification instead of the usual follow-up.