causes of missing mammographic lesions

Causes of missing mammographic lesions

• Dense parenchyma that obscures a lesion• Poor positioning or technique• Lesion location outside the field of view• Lack of perception of an abnormality that is

present • Incorrect interpretation of a suspect finding• Subtle features of malignancy• A slowly changing malignancy

• . Breast cancers are easily missed when they appear as focal areas of asymmetry or distortion (eg, invasive lobular carcinoma)

• when their appearance suggests a benign cause (eg, medullary and mucinous [colloid] invasive ductal carcinomas, which usually manifest as mostly circumscribed masses).

• Bird et al (6) found that 77 of 320 cancers (24%) in a screening population were missed, primarily due to dense breasts and a developing density that was not identified by the radiologist

• Goergen et al (7) found that cancers missed at screening

mammography were significantly lower in density and were more often seen on only one of two views than were detected cancers

Dense Breast, Palpable mass, BIRADS0

Any patient with dense breast parenchyma, a palpable mass, and negative mammographic findings should undergo US for further evaluation of the mass.

Obscuerd mass BIRADS0

BIRADS2

The negative predictive value of US with mammography for a palpable lesion to be 99.8% and 100%, respectively. Moy et al (11) found the negative predictive value of US with mammography for a palpable mass to be 97.4%. However, a palpable mass that appears solid at US warrants further evaluation with biopsy.

POOR POSITIONING

PROPER POSITIONING BIRADS0

Creative Additional Views &Positioning

LAT MED Oblique View

Cleavage View

craniocaudal RL = “craniocaudal rolled laterally”). craniocaudal RL = “craniocaudal rolled laterally”).

Improper Imaging Technique

Proper image

Radiologists’ Errors

• Lack of Perception• Satisfaction of search• Error of Interpretation• Do not compare with Previous study

MIRROR IMAGE INTERPRETATION

Mirror Image Interpretation

SUBTLE FINDING MIRROR

MISSED CA SATISFACTION OF SEARCH

NIPPLE TO LESION -ARC MEASUREMENT

MUCNOUS CIRCUMSCRIBED CA

NEW ASYMMETRIC DENSITY ILCA

Slow Growing CA

Tubular CA

ConclusionAlthough mammography is the standard of reference for the detection of early breast cancer, as many as 30% of breast cancers may be missed. To reduce the possibility of missing a cancer, the radiologist should take the following steps when interpreting mammographic findings:• Do not rely on screening views alone to diagnose a detected

abnormality; complete the evaluation with diagnostic mammography.• Review clinical data and use US to help assess a palpable or

mammographically detected mass.• Be strict about positioning and technical requirements to optimize

image quality.• Be alert to subtle features of breast cancers.• Compare current images with multiple prior studies to look for subtle

increases in lesion size.• Look for other lesions when one abnormality is seen.• Judge a lesion by its most malignant features.

Summary of Mammographic Report & BIRADS

Reporting Mammogram Using BIRADS

• Brief description of reason for the MMG• Brief description of the type• Comparison with previous MMG• Description of finding• Final assessment categories• Recommendation

BIRADS0, Recommendations

• Dense Breast in screening ,young high risk: MRI• Dense Breast & Palpable Mass: US, Solid, complex

cyst: CNB, Thick- wall cyst: Aspiration• Mass without fat or characteristic Mic Cal: US,

Solid, <5mm suspicious: VAB, circumscribed: local Mag view

• Absence of previous exam• Indeterminate findings: Additional views

BIRADS 1, negative for malignancy

• Normal fatty breast: Routine FU• Negative symmetrical SFG, No change or

neodensity: FU• Heterogeneously symmetrical dense, no

pertinent finding, no change or neodensity, may recommend US

BIRADS2, Benign finding

• An intra mammary lymph node• Benign mic cals• Fat contained masses• Thin -wall cysts with or without Int echo

BIRADS2

Tangential spot magnification mammogram, obtained after placement of an external marker,BIRADS2

Oil cyst

Rod shape cal

Milk of Calcium

Cystic milk alkaline cal

BIRADS3, Probably benign,<%2 malignancy, Short term FU

• An oval shape, well- defined, circumscribed or macro lobulated mass which is solid, isoechoic, and parallel on US: 6, 12, 24 moths FU, increased size of %25 : CNB

• Monomorph cluster Mic cal: 6,12, 24 months FU

• Focal asymmetry+ nonpalpable+ negative US

B3 became B4

B3 became B2

BIRADS4a, 3-30% malignancy, VAB or CNB

• Probably benign appearance with a tail or mild inhomogeneity on US

• Probably benign but hypo echoic mass• Intra cystic mass, intra ductal papilloma :VAB• Thick wall cyst : Aspiration• Indeterminate Amorphus cluster Mic cal: VAB• Developing density• Focal asymmetry+ palpable lump+ Neg US

Type 2 complex cyst+ doppler,BIRADS4a, CNB

Papillary apocrine hyperplasia with atypical ductal hyperplasia

Infiltrating Ductal Ca

Complex cyst, irregular thick wall

Coarse Hetergenously cluster cal

BIRADS4b 30- 60% malignancy, VAB or CNB

• Round circumscribed masses• Round hypo echoic masses• Structural distortion without history of surgery

or infection: VAB• New asymmetry: VAB

Fine pleomorphic cluster cal

New Amorph cal

BIRADS4c,% 60-95 malignancy

• No classic of malignancy, VAB or CNB • For example: micro lobulated mass

Fine pleomorphic, linear distribution

BIRADS 5, >%95 malignancy

• Speculated mass<5mm: VAB, >5mm: CNB• New density with irregular border < 5mm:

VAB, >5mm: CNB• Linear branching pleomorphic, fine linear or

pleomorphic linear or segmentally distributed cluster mic cal: VAB

Fine linear Seg distributed cal

Linear & amorph cal in a duct

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