What are the next steps for a patient with a BI-RADS (Breast Imaging-Reporting and Data System) 3 classification, indicating probably benign findings?

Management of BI-RADS 3 (Probably Benign) Findings

For this patient with BI-RADS 3 findings on left breast imaging, follow the standard surveillance protocol: perform unilateral diagnostic mammography of the left breast at 6 months, then bilateral mammography at 12 months, followed by continued surveillance every 6-12 months until completing 1-2 years of stable imaging, after which routine screening resumes. 1, 2

Initial 6-Month Follow-Up

• Perform a unilateral diagnostic mammogram of the left breast (the index breast) at 6 months from the initial BI-RADS 3 assessment 1, 2
• This initial short-interval follow-up is critical, as research demonstrates that 57.8% of malignancies in BI-RADS 3 lesions are detected at or before 6 months, validating the necessity of this early surveillance 3
• The cancer yield at 6-month follow-up is approximately 1.5%, with 15.2% of biopsied lesions proving malignant 3
• 79.4% of all malignant BI-RADS 3 lesions are identified at the 6-month mammogram, making this the most critical surveillance timepoint 4

Subsequent Follow-Up at 12 Months

• At 12 months, perform bilateral mammography since this patient is in the screening age group (this ensures the contralateral breast receives appropriate annual imaging) 1, 2
• The cancer yield at 12-month follow-up is approximately 1.2%, with 18.9% of biopsied lesions proving malignant 3
• 88.2% of malignant lesions are detected within the first 12 months of surveillance 4

Continued Surveillance Through 24 Months

• Continue follow-up imaging every 6-12 months for a total surveillance period of 1-2 years, with the interval determined by the level of clinical concern 1, 2
• The cumulative cancer yield through 2-year follow-up is 1.86%, which falls within the acceptable <2% malignancy rate for BI-RADS 3 classification 3
• Research suggests that 18-month follow-up may be omitted (proceeding directly from 12 to 24 months), as only 0.04% of lesions prove malignant at 18 months and only 1.7% of biopsies performed at 18 months are malignant 4

Criteria for Biopsy During Surveillance

• Perform biopsy if any interval mammogram shows the lesion has increased in size or its benign characteristics have changed 1, 2
• Biopsy is also indicated if clinical suspicion increases during the follow-up period 1

Return to Routine Screening

• If the lesion remains stable or resolves mammographically throughout the 1-2 year surveillance period, the patient should resume routine annual screening intervals 1, 2

Alternative: Immediate Biopsy

• Initial biopsy with histologic sampling may be considered instead of surveillance in specific circumstances 1, 2:
  • Patient has high anxiety about the finding 1
  • Patient strongly desires biopsy rather than surveillance 1, 2
  • Strong family history of breast cancer 1, 2
  • Uncertainty about patient's ability to return for follow-up visits 1, 2

Important Caveats

• The nodular pattern noted in the upper inner quadrant on ultrasound showed no suspicious findings and no geographic correlation with palpable abnormality, supporting the BI-RADS 3 assessment 1
• Scattered cysts identified bilaterally are benign findings (BI-RADS 2) and require no additional follow-up beyond routine screening 1
• Breast MRI is not routinely recommended for surveillance of BI-RADS 3 lesions, though it may have utility as a problem-solving tool in select non-calcified lesions 5, 6
• The overall biopsy rate during BI-RADS 3 surveillance is approximately 11.2%, with most biopsies occurring at the 6-month timepoint 3