A 28-year-old woman presents with a 1.5 cm mass in the left breast that she discovered 3 months ago. On examination, the mass is firm, mobile, non-tender, and located in the upper outer quadrant. She reports no family history of breast cancer and is on combined oral contraceptives. Ultrasound shows a well-defined, hypoechoic lesion with a thin echogenic rim and no posterior acoustic shadowing. The radiologist reports BI-RADS 3 (probably benign). What is the most appropriate management?

Explanation

## BI-RADS 3 Classification and Management **High-Yield:** BI-RADS 3 lesions are **probably benign** with a malignancy risk of <2%. The standard management is **imaging surveillance**, not biopsy or excision. ### BI-RADS Classification Summary | BI-RADS | Risk of Malignancy | Management | |---------|-------------------|-------------| | 1 | Negative | Routine screening | | 2 | Benign | Routine screening | | 3 | Probably benign (<2%) | Short-term imaging follow-up | | 4 | Suspicious (2–95%) | Biopsy recommended | | 5 | Malignant (>95%) | Biopsy/excision | | 6 | Known malignancy | Treatment | ## Imaging Follow-up Protocol for BI-RADS 3 **Key Point:** BI-RADS 3 lesions require **short-term imaging surveillance** to document stability and exclude malignancy. The typical protocol is: 1. **Ultrasound at 3 months** — assess for interval change 2. **Ultrasound at 6 months** — confirm stability 3. **Annual ultrasound for 2 years** — long-term surveillance If the lesion remains stable over 2 years, it can be reclassified as BI-RADS 2 and returned to routine screening. **Clinical Pearl:** The thin echogenic rim (capsule) and lack of posterior shadowing are reassuring features of a benign lesion, consistent with fibroadenoma or phyllodes tumour (low-grade). ## Why Biopsy Is Not Indicated **Warning:** The malignancy risk for BI-RADS 3 is <2%, which is **below the threshold for biopsy**. Performing biopsy on all BI-RADS 3 lesions would result in unnecessary invasive procedures and patient anxiety. Biopsy is reserved for BI-RADS 4 and 5 lesions. ## Why Other Options Are Incorrect | Option | Reason | |--------|--------| | Immediate wide local excision | BI-RADS 3 lesions have <2% malignancy risk; excision without biopsy confirmation is not justified and exposes the patient to unnecessary surgery. | | FNAC followed by conditional excision | FNAC is inadequate for breast lesions; core needle biopsy is the gold standard. Moreover, biopsy is not indicated for BI-RADS 3. | | Core needle biopsy | Biopsy is not indicated for BI-RADS 3 lesions; it is reserved for BI-RADS 4 and 5 (suspicious or malignant). |