A benign breast lesion such as a fibroadenoma typically presents on ultrasound with which orientation?

• A. Wider-than-tall
• B. Taller-than-wide
• C. Round with irregular margins
• D. Spiculated margins

Answer: (A)

Benign breast lesions like fibroadenomas tend to grow parallel to the tissue planes, so they are seen as wider-than-tall on ultrasound. This means the lesion’s horizontal dimension is greater than its vertical (anterior–posterior) dimension when you view it in the standard planes. This flat, parallel orientation reflects a well‑circumscribed, oval shape that typically extends along the breast tissue rather than into it. In contrast, malignant lesions often invade across tissue planes and appear taller-than-wide, which is why a wider-than-tall appearance is characteristic of a benign fibroadenoma. Round lesions with irregular or spiculated margins would raise suspicion for cancer, and a taller-than-wide orientation would also be concerning.