| Category | Assessment | Malignancy Risk | Clinical Interpretation | Recommended Action |
|---|---|---|---|---|
0 |
IncompleteNEEDS EVALUATION |
—
|
Requires additional imaging evaluation and/or prior mammograms for comparison; assessment cannot be completed from current images alone | Additional Imaging |
1 |
NegativeNO ABNORMALITY |
0%
|
No abnormality detected; breasts are symmetric; no masses, architectural distortion or suspicious calcifications identified on imaging | Routine Screening |
2 |
BenignDEFINITELY BENIGN |
0%
|
Benign findings recorded for reference; includes simple cysts, intramammary lymph nodes, stable fat-containing lesions, fibroadenomas with calcifications | Routine Screening |
3 |
Probably BenignSHORT-TERM FOLLOW-UP |
< 2%
|
Finding has high probability of being benign; not expected to change, but short-term follow-up is prudent to confirm stability; biopsy if stability not confirmed at 2–3 years | 6-Month Follow-Up |
| ◆ Category 4 — Suspicious (Subdivided 4A · 4B · 4C) · Tissue sampling recommended for all | ||||
4A |
Low SuspicionBIOPSY RECOMMENDED |
2 – 10%
|
Low suspicion for malignancy; requires tissue sampling; if benign concordant result obtained, 6-month follow-up imaging is acceptable management | Tissue Biopsy |
4B |
Moderate SuspicionBIOPSY REQUIRED |
10 – 50%
|
Moderate suspicion; tissue sampling required; close radiologic-pathologic correlation is essential; discordant benign result requires repeat biopsy or surgical excision | Biopsy + Correlation |
4C |
High SuspicionSTRONGLY SUSPICIOUS |
50 – 95%
|
High suspicion; malignant pathology result expected; discordant benign histology should prompt immediate repeat biopsy or surgical referral without delay | Urgent Biopsy |
5 |
Highly SuggestiveOF MALIGNANCY |
≥ 95%
|
Highly suggestive of malignancy; appropriate action should be taken; biopsy required; neoadjuvant systemic therapy may be initiated prior to definitive surgical management | Biopsy + Treatment |
6 |
Known MalignancyBIOPSY-PROVEN |
N/A
|
Biopsy-proven malignancy prior to definitive therapy; imaging used to assess extent of disease, treatment response to neoadjuvant chemotherapy, or pre-surgical planning | Surgical / Oncology |
| Modality | Primary Use | Key Descriptors | Modality-Specific Notes |
|---|---|---|---|
| Mammography2D / 3D TOMO | Primary screening modality; annual screening from age 40–50 (guideline-dependent); diagnostic mammography for symptomatic patients | Masses · Calcifications | Describes masses (shape, margin, density), calcifications (morphology, distribution), architectural distortion, asymmetries. Tomosynthesis (3D) reduces recall rates and improves cancer detection vs 2D alone. |
| UltrasoundTARGETED / WHOLE BREAST | Problem-solving for mammographic findings; first-line in patients <30 years or pregnant; characterises palpable lumps; guides biopsy procedures | Shape · Margin · Echo | Assesses mass shape (oval/round/irregular), orientation, margin (circumscribed/spiculated), echo pattern (anechoic/hypoechoic), posterior acoustic features. Elastography adjunct for stiffness characterisation. |
| Breast MRICONTRAST-ENHANCED | High-risk screening (BRCA carriers); pre-surgical staging; evaluate treatment response; occult primary breast cancer; implant integrity assessment | Kinetics · Enhancement | Evaluates focus, mass, non-mass enhancement (NME); kinetic curve analysis (initial rise + delayed phase); background parenchymal enhancement (BPE); highest sensitivity (~95%) but lower specificity than mammography. |
| Category | Immediate Action | Follow-Up Interval | Pathway Detail & Rationale |
|---|---|---|---|
0 |
Recall / Add Views | Immediate / ASAP | Obtain additional imaging: spot compression, magnification views, ultrasound correlation, or comparison with prior studies. Do not issue a management recommendation until assessment is complete. |
1 |
Routine Screening | Annual (age-appropriate) | Continue age-appropriate routine mammographic screening. No additional workup required. Negative report should explicitly state no abnormality to reduce patient anxiety. |
2 |
Routine Screening | Annual (age-appropriate) | Benign finding documented for radiological record. No biopsy or additional imaging required. Examples: simple cysts, oil cysts, milk of calcium, fibroadenoma with coarse calcifications. |
3 |
Short-Interval Imaging | 6 months → 12 → 24 months | Initial 6-month follow-up of affected breast, then bilateral imaging at 12 and 24 months. If stable over 2–3 years → upgrade to BI-RADS 2. If increased in size or changed morphology → upgrade to BI-RADS 4 and biopsy. |
4A |
Tissue Sampling | Post-biopsy 6-month follow-up | Core needle biopsy (CNB) or vacuum-assisted biopsy (VAB). If result is benign and concordant with imaging → 6-month short-interval follow-up acceptable. Discordant result → repeat sampling. |
4B |
Biopsy + Correlation | Pathology review within 5 days | CNB mandatory; close radiologic-pathologic correlation required. Benign concordant result may be followed; discordant or high-risk histology (ADH, ALH) requires surgical excision or MDT discussion. |
4C |
Urgent Biopsy | Urgent pathology review | CNB with clip marker placement; urgent pathology review. Any benign result that is discordant with high-suspicion imaging requires immediate repeat biopsy or surgical excision — do not accept discordant benign results. |
5 |
Biopsy + Oncology | MDT referral within 2 weeks | CNB with marker clip; refer to breast MDT. Neoadjuvant chemotherapy may be initiated after biopsy confirmation to downstage disease before surgery. Staging CT/PET may be indicated. |
6 |
Active Treatment | Interim response imaging | Imaging used to assess extent of disease, tumour response to neoadjuvant chemotherapy (mid-treatment and pre-surgical), and surgical planning (BCS vs mastectomy). MRI preferred for treatment response assessment. |
| Type | Topic | Detail |
|---|---|---|
| Pearl | Dense Breast Tissue | Heterogeneously or extremely dense breasts (ACR C/D) reduce mammographic sensitivity to ~40–60%. Supplemental ultrasound or MRI screening should be discussed. Dense tissue is an independent risk factor for breast cancer. |
| Pearl | High-Risk Screening | Patients with ≥20% lifetime risk (BRCA1/2, TP53, strong family history) should receive annual breast MRI in addition to mammography from age 25–30. MRI sensitivity ~95% vs mammography ~40% in BRCA carriers. |
| Caution | BI-RADS 3 in Diagnostic Setting | BI-RADS 3 should not be assigned in a diagnostic (symptomatic) setting or after incomplete workup. It is only appropriate when additional views and ultrasound correlation have been performed and the probability of malignancy is demonstrably <2%. |
| Caution | Pregnancy & Lactation | Ultrasound is first-line in pregnant/lactating women. Mammography is safe during pregnancy (low radiation dose). MRI without gadolinium acceptable; gadolinium contrast avoided in first trimester; used cautiously thereafter. |
| Pitfall | Discordant Pathology | Radiologic-pathologic discordance is the most critical pitfall: a benign biopsy result for a BI-RADS 4C or 5 lesion must NOT be accepted. False negative CNB rates of 1–3% exist; discordance mandates repeat sampling or surgical excision. |
| Pitfall | Bilateral Synchronous Lesions | Assign individual BI-RADS category to each lesion and each breast. The overall assessment should reflect the most actionable (highest) category finding. Do not average or combine findings from different breasts. |
| Limitation | Male Breast Disease | BI-RADS lexicon is validated primarily in females. Application in male breast is extrapolated. Gynaecomastia can be BI-RADS 2 if classic subareolar pattern. Eccentric, hard or ulcerated lesions should be promptly biopsied regardless of imaging appearance. |
| Limitation | Implants | Standard 2-view mammography is supplemented by implant-displaced (Eklund) views. Breast tissue posterior to implant may be incompletely visualised. Ultrasound and MRI are adjuncts for implant integrity and parenchymal evaluation. |