Breast imaging lexicon: mammography

Lalita Huntrakul, M.D.

Department of Radiology

Faculty of Medicine ChiangMai University

Breast imaging lexicon

• Diversity of terminology may cause confusion

• Approved by the ACR Committee on BIRADS

• Report will be clear, concise and standardized

• Consistent use of BIRADS assessment categories coupled with use of concordant management recommendations.

Breast composition 2003 BI-RADS® Atlas (4 th Edition) 2013 BI-RADS® Atlas (5 th Edition)

1. The breast is almost entirely fat (<25% glandular)

1. The breasts are almost entirely fatty

2. There are scatter fibroglandular densities (approximately 25%-50% glandular)

2. There are scattered areas of fibroglandular density

3. The breast tissue is heterogeneously dense, which could obscure detection of small masses (approximately 51% - 75% glandular)

3. The breasts are heterogeneously dense, which may obscure small masses

4. The breast tissue is extremely dense. This may lower the sensitivity of mammography (>75% glandular)

4. The breasts are extremely dense, which lowers the sensitivity of mammography **(Quartiles have been eliminated)

A. MASSES

• 3 dimentional and occupies space.

• Seen in two different mammographic projections.

• Complete or partially convex-outward borders

• Denser in center than periphery

Asymmetry: similar to other discrete fibroglandular tissue, except there are unilateral, no mirror image

(compare to the opposite breast) Concave-outward

Interspersed with fat

A. MASSES

1. shape

Oval Elliptical or egg-shaped (2-3 undulations)

Round Spherical, ball-shaped, circular, globular

Irregular Neither round nor oval Implies a suspicious findings

*Lobular 2-3 large undulation, descriptor of shape Eliminated

Confused with microlobulated (many small undulation, descriptor of margin) and usually implies a suspicious mass

A. MASSES

2. Margin

Circumscribed (well or sharply

defined)

- Abrupt transition between lesion and surrounding tissue - At least 75% must be well defined - Any indistinct, microlobulated or spiculated base on the most suspicious component)

Obscured Circumscribed but hidden by fibroglandular tissue (>25%)

Microlobulated - Short cycle (many small) undulation - Suspicious finding

Indistinct (ill-defined)

- No clear entire or any demarcation of the margin - Different from obscured - Suspicious finding

Spiculated - Lines radiating from mass - Suspicious finding

A. MASSES

3. Density

High - Greater than fibroglandular tissue - likelihood of malignancy 70 %

Equal - Same density with fibroglandular tissue

Low - Density less than fibroglandular tissue

Fat-containing - Fat density: oil cyst, lipoma, galactocele, hamartoma. - Almost always benign

B. CALCIFICATIONS

• The most common finding in MMG

• The most difficulty to identify and interpreted.

2003 BI-RADS® Atlas (4th Edition) 2013 BI-RADS® Atlas (5th Edition)

Calcifications

Typically Benign

Lucent-Centered

Lucent-Centered eliminated to simplify reporting

Rim calcification

Eggshell Eggshell" eliminated to simplify reporting

Calcifications

Intermediate Concern

Suspicious Morphology (a single category replaces previous 2 categories)

**clinical studies in the intervening time showed small differences in the likelihood of malignancy**

Higher Probability Malignancy

B. CALCIFICATIONS Findings Terms

B. Calcifications

1. Typical benign

a. Skin b. Vascular c. Coarse or “popcorn-like” d. Large rod-like e. Round f. Rim g. Dystrophic h. Milk of calcium i. suture

2. Suspicious morphology

a. Amorphous b. Coarse heterogeneous c. Fine pleomorphic d. Fine linear or linear branching

3. Distribution

a. Diffuse b. Regional c. Grouped d. Linear e. segmental

Skin

- Usually lucent-centered - MC along inframammary fold, parasternal, axilla and areolar. - Tightly grouped, overall <5 mm - Additional tangential view

Vascular - Parallel tracks or linear tubular calcification - Clearly associated with blood vessel.

Coarse or popcorn-like - Large (>2-3 mm) - Involuting fibroadenoma (peripheral locate in a circumscribed mass)

Large rod-like

- Ass. Duct ectasia - Smooth linear rod (≥ 5 mm) - Follow ductal distribution radiating toward nipple - Usually bilateral - Usually older than 60 years.

Round - Usually < 1 mm (punctate <0.5 mm); diffuse benign - Isolate group of punctate : probably benign - New, increasing, linear or segmental arrangement: suspicious finding

Rim

- Calcium deposit in surface < 1 mm thick < 1 mm to > 1 cm or more - Round or oval, smooth, lucent-centered - Fat necrosis (thicker rim), calcified cyst wall

Dystrophic

- RT, trauma or surgery - Irregular shape > 1 mm - Often lucent center

Milk of calcium

- Sediment calcification in cyst - Usually grouped **Apparent change in shape on Different MMG projection : CC is smudgy : MLO or LM/ML is semilunar, crescent, curvilinear (concave up) or linear

Suture Calcium deposit of suture material

B. CALCIFICATIONS Findings Terms

B. Calcifications

1. Typical benign

a. Skin b. Vascular c. Coarse or “popcorn-like” d. Large rod-like e. Round f. Rim g. Dystrophic h. Milk of calcium i. suture

2. Suspicious morphology

a. Amorphous b. Coarse heterogeneous c. Fine pleomorphic d. Fine linear or linear branching

3. Distribution

a. Diffuse b. Regional c. Grouped d. Linear e. segmental

Suspicious morphology

Morphology Likelihood of malignancy BIRADS

Amorphous 21%

4B Coarse

heterogeneous 13%

Fine pleomorphic 29%

Fine linear or linear branching 70% 4C

Amorphous (indistinct)

- Small and/or hazy - Specific particle shape cannot be determined - Grouped, linear, or segmental suspicious and should be Bx (4B) - Bilateral, diffuse usually may be dismissed as benign - Base line magnification

Coarse heterogeneous

- Size between 0.5-1.0 cm - Variable in size and shape - Smaller than dystrophic: similar and >1mm) - Multiple bilateral grouping almost always fibroadenoma - Solitary isolated, chance of malignancy (4B)

Fine pleomorphic

- More conspicuous than amorphous - Vary in size and shape and <0.5 mm. - (fine pleomorphic >coarse heterogeneous>popcorn-like>dystrophic) - Malignancy likelihood increased as the size decreases. - BIRADS 4B

Fine linear or linear branching

- Thin, linear, irregular and may discontinuous and branching - Size <0.5 mm. - Highest PPV for malignancy (70%) - BIRADS 4C

B. CALCIFICATIONS Findings Terms

B. Calcifications

1. Typical benign

a. Skin b. Vascular c. Coarse or “popcorn-like” d. Large rod-like e. Round f. Rim g. Dystrophic h. Milk of calcium i. suture

2. Suspicious morphology

a. Amorphous b. Coarse heterogeneous c. Fine pleomorphic d. Fine linear or linear branching

3. Distribution

a. Diffuse b. Regional c. Grouped d. Linear e. segmental

Distribution • Indicate the arrangement of calcifications

• Important morphology in evaluating the likelihood of malignancy

Distribution Likelihood of malignancy

Diffuse 0

Regional 26%

Grouped 31%

Linear 60%

Segmental 62%

Diffuse (scattered) - Randomly throughout the breast - Diffuse punctate and amorphousalmost always benign, esp.

bilaterally.

Regional

- Occupying in large portion of the breast (greatest dimension >2 cm)

- Not conforming to a duct - Malignancy is less likely (don’t forget to evaluate morphology)

Grouped (clustered) - Occupying in small portion of the breast - At least 5 calcification are grouped with 1 cm area - Upper limit are large number of calcification within 2 cm.

Linear - Array in line - Elevate the degree of suspicious for malignancy - **vascular and rod like have characteristic morphology**

Segmental - Deposition in duct and their branches. - Elevate the degree of suspicious for malignancy - **Rod-like have characteristic morphology**

Distribution

C. ARCHITECTURAL DISTORTION

• Parenchyma is distorted without mass visible

• Thin straight line or spiculation radiating from a point with parenchymal retraction

• May associated with asymmetery, calcification

• No Hx or trauma or Sx, DDx malignancy or radial scar Biopsy

D. ASYMMETRIES

BIRADS 2003 BIRADS 2013

Global Asymmetry Separate category

“Asymmetries”

1. Asymmetry** 2. Global Asymmetry 3. Focal Asymmetry 4. Developing Asymmetry Focal Asymmetry

• Unilateral deposition of fibroglandular tissue

• Not conforming to definition of mass • Concave-outward border • Interspread with fat

Mass: convex-outward

Denser in center than periphery

1. Asymmetry

- Discrete asymmetric area of fibroglandular tissue that visible on only one MMG projection.

- 80% summation artifact - Additional view should be obtained

2. Global asymmetry

- Visible on two MMG projections. - Large portion of breast, at least one quadrant - Non-palpable - Usually normal variant - BIRADS 2

3. Focal asymmetry

- Like global asymmetry but smaller (Less than a quadrant) - More concerning: esp size < 1 cm. - Malignancy likelihood 0.5%-1% (BIRADS 3) - 0% likelihood of malignancy if stable at least 2-3 yrs.

4. Developing asymmetry

- New or larger density or more conspicious - Hx Sx, trauma, infection - Additional image - BIRADS 4

D. ASYMMETRIES

E. INTRAMAMMARY LYMPH NODE

• Circumscribed mass, reniform shape and have hilar fat

• Size ≤ 1 cm, larger than 1 cm (with hilar fat)

• Anywhere, but frequent at lateral and upper portion of breast, close to axilla

F. SKIN LESION

• Area of radiolucency surrounding the lesion

• Should be marked by the techonologist

G. SOLITARY DILATED DUCT

• Unilateral tubolar or branching structure

• Rare finding (report: 10% malignancy)

• Additional imaging evaluation

H. ASSOCIATED FEATURES Terms

1. Skin retraction Skin is pulled in abnormality

2. Nipple retraction New finding ≠ inverted nipple (bilateral and congenital)

3. Skin thickening Focal or diffuse >2 mm thick RT

4. Trabecular thickening

Thickening of fibrous septa Edema, RT

5. Axillary lymphadenopathy

6. Architectural distortion

Conjunct with another finding

7. Calcifications Conjunct with other finding

5. Axillary lymphadenopathy

• New, larger or ,rounder

5. Axillary lymphadenopathy

Unilateral

Infection or inflammation cause (breast, axilla and extremity): mastitis, abscess, infected skin, cat-scratch fever, post vaccination, etc…

BIRADS 2

Absent of known infectious or inflammatory cause: occult breast CA less common: lymphoma,

metastasis

BIRADS 4

5. Axillary lymphadenopathy

Bilateral

Reactive/Infectious/inflammation (frequent): sarcoidosis, SLE,

psoriasis, HIV, etc BIRADS 2

Known lymphoma, leukemia

Based on breast finding followed by “with bilateral

axillary lymphadenopathy due to known…..”

• No known explanation cause • New finding

BIRADS 4

I. LOCATION OF LESION

1. Laterality Right or left breast

2. Quadrant and clock face

DO NOT REQUIRE CLOCK-FACE LOCATION 1. Central: directly behind the nipple areolar complex on all projection 2. Retroareolar: anterior third of the breast, close to nipple 3. Axillary tail: UOQ adjacent to axilla but within breast mound

3. Depth Anterior, middle and posterior third

4. Distance from the nipple