BIRADS 2 Mammogram: Benign Findings
A BIRADS 2 classification on mammogram indicates benign findings with no evidence of malignancy, requiring only routine annual screening mammography without any need for additional imaging, short-term follow-up, or biopsy. 1, 2
What BIRADS 2 Means
BIRADS 2 is essentially a negative mammogram that identifies specific benign findings that the radiologist chooses to describe in the report. 1 This category carries zero risk of malignancy. 3
Typical Findings in BIRADS 2
The following are common benign findings that warrant a BIRADS 2 classification: 1, 2
- Benign-appearing calcifications (such as calcifying fibroadenomas)
- Oil cysts
- Lipomas
- Intramammary lymph nodes
- Vascular calcifications
- Breast implants
- Architectural distortion clearly related to prior surgery
Clinical Management
For BIRADS 2, the recommendation is to resume routine screening mammography in 1 year. 1, 2 No additional imaging, diagnostic workup, or biopsy is indicated. 1, 2
Evidence Supporting Zero Malignancy Risk
A retrospective study of 192 patients with breast lesions classified as BIRADS 2 on MRI (similar classification system) demonstrated 0% malignancy rate (0 of 192 lesions were malignant). 3 Of these, 67 lesions underwent histopathologic verification showing exclusively benign findings, while the remaining 125 showed no changes during 2-9 years of follow-up. 3 This confirms that breast biopsies are unnecessary for BIRADS 2 lesions. 3
Key Clinical Distinctions
Understanding where BIRADS 2 fits in the classification system helps contextualize its benign nature: 1, 2
- BIRADS 1 (Negative): No findings at all
- BIRADS 2 (Benign): Benign findings present but definitively not malignant
- BIRADS 3 (Probably Benign): <2% malignancy risk, requires 6-month follow-up
- BIRADS 4 (Suspicious): Biopsy recommended
- BIRADS 5 (Highly Suspicious): ≥95% malignancy probability, biopsy required
Important Caveats
When multiple abnormalities are present, the overall BIRADS assessment is based on the most worrisome finding. 1, 2 If both mammography and ultrasound are performed, the BIRADS category represents cumulative findings from both modalities, and the category may change based on subsequent imaging. 1, 2
The radiologist should attempt to obtain prior mammograms for comparison, particularly when evaluating any questionable areas, though this is less critical for clearly benign BIRADS 2 findings. 1