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Missed Breast Carcinoma:

Pitfalls and Pearls Presented by : dr Rivani Kurniawan

Lecturer : dr Hari Soekersi SpRad(K)

Aneesa S. Majid, MD et all

RSNA,• radiographics.rsnajnls.org



Introduction

• Mammography is the standard of reference for the

early detection of breast cancer

• Screening mammography is performed to detect anabnormality, whereas diagnostic mammography isused to further evaluate the abnormality or a clinical

problem.



• According to data from the Breast Cancer DetectionDemonstration Project, the false-negative rate ofmammography is approximately 8%– 10%

• After evaluating retrospective versus blindedinterpretations of mammograms, others have

concluded that the rate of missed breast cancers is ashigh as 35%



• In a series of 150 mammograms read by 10

radiologists, immediate work-up of the true cancerswas recommended in 74%– 96% of cases

• Recent studies have emphasized the use ofalternative imaging modalities to detect and diagnose

breast carcinoma, including ultrasonography (US),magnetic resonance (MR) imaging, and nuclear medicine studies



Breast cancers may be missed

because of ( 7 tools ) :

•Dense parenchyma that obscures a lesion

•Subtle features of malignancy

•A slowly changing malignancybreast

•Poor potitioning

•Poor techniquetechnologist

•Lack of perception of an abnormality that ispresent

•Incorrect interpretation of a suspect findingradiologist



Dense parenchym

Breast parenchym

•

Noncalcified mass•Nondistorting lession

•areas of tethering or disruption oforientation of normalparenchymalelements

radiologist

•

architecturaldistortion

• faintmicrocalcifications



Invasive ductal carcinoma in a 36-year-old woman with dense breastsand a palpable mass.A Left mediolateral oblique mammogramB US image obtained in the area of the palpable abnormality



U l t r a

s o n o r

a p h y

determining the presence of a solid mass thatcorresponds to an area of distortion

characterizing palpable masses in dense tissue

evaluation of asymmetric densities seen atmammography



Invasive lobular carcinoma

in a 40-year-old woman withdense breasts..A. Right mediolateral obliquescreening mammogramB. US image of the massdemonstrates a simple cyst

C. US image



Poor Positioning

Proper positioning andimage contrast are

absolutely necessary in allaspects of radiology,

especially in mammography

The technologist must adhere tothe positioning standards to

maximize the amount of tissueincluded on the image



Proper positioning(a) Left mediolateral oblique (left) and craniocaudal

(right) mammograms(b) On a left mediolateral oblique mammogram

obtained with improved positioning



• Creative positioning may be necessary to includeareas of palpable abnormalities on the images :

Radiopaque markers

Spot compression



Creative positioning may also be helpful in :

patients who are tense

who have suffered a stroke

who have shoulder problems

other debilitating factors that limit visualization of theposterior breast on standard mediolateral obliqueviews



Creative positioning for lesion detection(a) Bilateral mediolateral obliqueMammograms(b) On a right lateromedialMammogram(c) Spot magnificationmammogram

P T h i



Poor Technique

optimize image contrast to avoidobtaining over or

underpenetrated images

Careful attention to dailyprocessor quality control is alsonecessary to optimize contrast

Proper positioning of thephotocell is necessary to achieve

correct optical density on theimage

The technologist should alwaysreview the images under proper

mammographic viewingconditions to assess the adequacy

of imaging technique

technologist



Proper imaging technique

(a) Rightcraniocaudal screening mammogram(b) Right mediolateral obliquemammogram(c) Right craniocaudal spot magnificationmammogram



lack of perception

- Two major causes ofmissed breast cancers are

related to radiologisterror

- Perception error occurswhen the lesion is included in

the field of view and is evidentbut is not recognized by the

radiologist



• The lesion may or may not have subtle features ofmalignancy that cause it to be less visible.

Small nonspiculated masses,

Areas of architectural distortion and asymmetry,

Small clusters of amorphous or faint

microcalcifications may all be difficult to perceive.



To avoid perception error :

• images should be reviewed as mirror images



• The radiologist should compare like areas onthe side-by-side images to identify any focalasymmetric density or low-density mass

Mirror image interpretation(a) Bilateral mediolateraloblique mammograms(b, c) On left craniocaudalspot compression

mammograms, the posterior (b) and anterior (c)



• Identification of a focal density should prompta search for this density on the correspondingview in the same arc from the nipple



• The radiologist must not be satisfied withfinding just one lesion, but must searchcarefully for others, whether benign or

malignant.

Satisfaction of search.Right mediolateral oblique (a)

and craniocaudal (b)mammograms



• MR imaging has been useful in identifying the primarycarcinoma when a metastatic node is found in theaxilla and mammographic findings are negative



Incorect interpretation

- The second major cause ofmissed breast cancers that isrelated to radiologist error isincorrect interpretation of a

lesion

- which occurs when anabnormality with suspect featuresis observed but is misinterpreted

as being definitely or at leastprobably benign



Several factors may lead to misinterpretation,such as

lack of experience

fatigue,

Inattention



• Characterization of a lesion that is identified at

screening mammography should be based ondiagnostic mammographic findings and not onscreening findings alone.

S btle Sig s of



Subtle Signs ofMalignancy

The cancers that are the most challenging todiagnose and that most often lead to

interpretation errors are those with subtle or indistinct features of malignancy



These features include

• areas of architectural distortion

• small groups of amorphous or punctatemicrocalcifi cations,

• focal asymmetric densities

• dilated ducts

• relatively well circumscribed masses



Circumscribed cancer in a 63-year-old woman.Right exaggerated craniocaudal lateral mammogram



US is helpful in predicting the likelihood ofmalignancy in a circumscribed mass

•

Simple cysts seen at US constitute a benignfinding.

• Solid lesions that are smooth, elliptic, and

wider than they are tall are probably benign



• masses that have irregular or angulated margins, aremarkedly hypo echogenic, and are taller than they arewide are probably malignant

• If, however, the mass is seen at US as a solid lesionwith worrisome features such as a “ taller-than-wide”

shape or irregular margins , biopsy is indicated



• Clinical history is important in evaluating focal

areas of asymmetry

• In the absence of tumor or infection, focaldeveloping densities should prompt further

assessment and, usually, biopsy



Slow-growing Cancers

• The doubling time for breast cancers has been

reported to range from 44 to 1,869 days

• However, malignant calcifi cations have beenreported to be stable at mammography for as

long as 63 months



• Therefore, a slowly changing cancer may go

undetected if the radiologist fails to compare findingswith those on older images

• A lesion with features that strongly suggestmalignancy but that has been stable for 1– 2 years still

requires biopsy because it may represent a slowlychanging cancer



Role of Double Reading

.Double reading ofmammograms hasbeen shown toincrease thedetection rate for breast cancer byup to 15% (29,30)

.Computer-aideddetection (CAD)represents arelatively newtechnology thathas beenimplemented insomemammography

facilities for double reading

.The sensitivity ofthe CAD systems isgreater for detectingcalcifications thanfor detectingmasses



Conclusions

• Although mammography is the standard of

reference for the detection of early breastcancer, as many as 30% of breast cancers maybe missed



To reduce the possibility of missing a cancer, theradiologist should take the following steps wheninterpreting mammographic fi ndings:

• 1. Do not rely on screening views alone to diagnose adetected abnormality; complete the evaluation withdiagnostic mammography.

•

2. Review clinical data and use US to help assess apalpable or mammographically detected mass



• 3. Be strict about positioning and technicalrequirements to optimize image quality.

• 4. Be alert to subtle features of breast cancers.

• 5. Compare current images with multiple prior studiesto look for subtle increases in lesion size.

•

6. Look for other lesions when one abnormality isseen.

• 7. Judge a lesion by its most malignant features.



TERIMA KASIH



Breast cancer risk factor

Gender

Aging

Genetic

Personal history of breast cancer

Race and ethnicity

Dense breast tissue

Menstrual periods

Previous chest radiation



BIRADS



BREAST PARENCHYMAL DENSITIY

• I. The breast is almost entirely fat

• II. There are scattered fibroglandular densities.

• III. The breast is heterogeneously dense. Thismay lower the sensitivity of mammography.

• IV. The breast tissue is extremely dense, whichcould obscure a lesion in mammography



• Findings on the mediolateral oblique view thatindicate proper positioning include:

visualization of the pectoralis muscle to the level ofthe nipple

A convex appearance of the pectoralis major muscle

Complete visualization of posterior breast tissue

Breast tissue that is well compressed and positioned inan up-and-out orientation

An open inframammary fold



Breast cancers may be missed



ybecause of ( 7 tools ) :

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



Causes of Missed Breast Cancers

Dense Parenchyma

• Breast parenchyma that is inherently dense

compromises the ability to detect a mass,especially a noncalcified, nondistorting lesion

• The radiologist must be particularly attentive

in searching for areas of architecturaldistortion or faint microcalcifications



• the tissue must be intensely evaluated for any areas oftethering or disruption of orientation of normal

parenchymal elements

• Unless it is documented as a postsurgical scar, an areaof architectural distortion must be further evaluated

with additional views (eg, spot compression, magnification, off-angle)



• US may also be helpful in determining the presence ofa solid mass that corresponds to an area of distortion

• US is very important in the evaluation ofmammographic abnormalities, being useful incharacterizing palpable masses in dense tissue and

circumscribed isodense masses



• US can be especially helpful in the evaluation ofasymmetric densities seen at mammography becauseit can help identify the density as either breast tissueor a true mass

• However, a palpable mass that appears solid at US

warrants further evaluation with biopsy



Poor Positioning

• Proper positioning and image contrast are absolutelynecessary in all aspects of radiology, especially inmammography

• The technologist must adhere to the positioningstandards to maximize the amount of tissue included

on the image



• At craniocaudal imaging, the technologist shouldverify that the breast is pulled straight forward and

not exaggerated laterally, and that the breast tissue iswell compressed.

• The difference between the posterior nipple line

measurement on the mediolateral oblique andcraniocaudal views should not exceed 1 cm



Poor Technique

• The technologist must:

optimize image contrast to avoid obtaining over or underpenetrated images

Proper positioning of the photocell is necessary to

achieve correct optical density on the image



• Careful attention to daily processor quality control isalso necessary to optimize contrast

• The technologist should always review the imagesunder proper mammographic viewing conditions toassess the adequacy of imaging technique .

• Image blur is problematic, particularly in theassessment of microcalcifi cations.



Lack of Perception

• Two major causes of missed breast cancers arerelated to radiologist error

• Perception error occurs when the lesion is included inthe field of view and is evident but is not recognizedby the radiologist



To avoid perception error :

o images should be reviewed as mirror images

o The radiologist should compare like areas on the side-by-side images to identify any focal asymmetricdensity or low-density mass.

o Identification of a focal density should prompt asearch for this density on the corresponding view in

the same arc from the nipple .

o Additional views may be needed to verify thepresence of a true lesion



• The radiologist should compare like areas onthe side-by-side images to identify any focalasymmetric density or low-density mass.



• Failure to diagnose multifocal and multicentric breastcancers can directly affect patient treatment.

• The radiologist must not be satisfied with finding justone lesion, but must search carefully for others,whether benign or malignant.



• The radiologist must not be satisfied withfinding just one lesion, but must searchcarefully for others, whether benign or

malignant.



• The primary breast cancer may be occult and either not observed or very subtle at mammography

• Careful attention to mirror image abnormalities or focal asymmetric densities is important in identifyingthe primary lesion



Incorrect Interpretation

• The second major cause of missed breast cancers thatis related to radiologist error is incorrect

interpretation of a lesion

• which occurs when an abnormality with suspectfeatures is observed but is misinterpreted as being

definitely or at least probably benign



• Misinterpretation may also occur if the radiologistfails to obtain all the views needed to assess thecharacteristics of a lesion or if the lesion is slowgrowing and prior images are not used for comparison.

•

The radiologist may erroneously judge theabnormality by its most benign features and missimportant malignant features that necessitate biopsy



Subtle Signs of



gMalignancy

The cancers that are the most challenging to

diagnose and that most often lead tointerpretation errors are those with subtle or indistinct features of malignancy



Role of Double Reading

• Double reading of mammograms has beenshown to increase the detection rate for breast cancer by up to 15% (29,30)

• Computer-aided detection (CAD) represents arelatively new technology that has beenimplemented in some mammography facilitiesfor double reading



• The sensitivity of the CAD systems is greater for detecting calcifications than for detectingmasses



• Asymmetric densities are frequently seen atmammography.

• These findings in isolation have a low positivepredictive value for malignancy

•

however, when they are associated withmicrocalcifications or architectural distortion, the riskof malignancy is increased

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