Targeted ultrasound of the left breast. Targeted ultrasound of the left breasts demonstrates a complex solid and cystic mass at the 3:00 position, 5 cm from the nipple. There is a posterior acoustic enhancement (orange arrows). This should not be confused with a "complicated cyst." Complex solid and cystic masses should be biopsied (BI-RADS 4).BI-RADS, Breast Imaging Reporting and Database System score.