Focal asymmetry in the middle third of the upper outer quadrant of the right breast is usually described on ultrasound examination of the breast, and is most often considered to be breast hyperplasia. Mammary hyperplasia is one of the most common benign breast diseases, often presenting as breast pain with nodules or lumps, and in some patients may be associated with nipple discharge. The diagnosis of breast hyperplasia requires more detailed mammograms and pathologic biopsies, which are difficult to determine by breast ultrasound alone. In addition, the ultrasound findings of focal asymmetry in the middle 1/3 of the upper outer quadrant of the right breast need to be interpreted in the context of the specific BI-RADS classification, which corresponds to different risks. Patients are advised to combine the opinions of the sonographer and clinician.