Case 34 Answer 2

No. This mass is microlobulated inferiorly, and much of the margin is indistinct (poorly defined) and obscured (by overlying breast tissue). To be "circumscribed", a mass must be well-defined (and not obscured) for at least 75% of its margin, and must lack more suspicious findings such as microlobulation and indistinct or spiculated margins.

An ultrasound was performed.

What is your final assessment?

• BI-RADS 2 - Benign - Appearance consistent with fibroadenoma
• BI-RADS 3 - Probably Benign - Likely a fibroadenoma
• BI-RADS 4 - Suspicious - Possibly a fibroadenoma, but warrants tissue diagnosis to rule out carcinoma
• BI-RADS 5 - Highly Suggestive of Malignancy - Highly likely to be cancer