Mistakes We All Make:Breast Imaging

Dr. Kalesha HackSunnybrook Health Sciences CentreDivision of Women’s Imaging

Mistakes We All Make:Breast Imaging

Dr. Kalesha HackSunnybrook Health Sciences CentreDivision of Women’s Imaging

DISCLOSURE

• I have no financial conflicts of interest to disclose

OBJECTIVES

• Identify common pitfalls in multi-modality breast imaging screening

• Identify common pitfalls in multi-modality breast imaging work-up

• Apply methods as a medical expert to avoid these common pitfalls

BACKGROUND

v “The important question isn’t how to keep bad physicians from harming patients; it’s how to keep good physicians from harming patients… The deeper problem with medical malpractice is that by demonizing errors they prevent doctors from acknowledging & discussing them publicly.”

v “Not only do all human beings err, but they err frequently and in predictable, patterned ways”

Dr. Atul Gawande, author of Complications, Better and Being Mortal

CASE 1RCC2013

RMLO 2013

CASE 1RCC2012

RMLO2012

CASE 1RCC2011

RMLO2011

CASE 12013 2012 2011

CASE 1

• “Right breast requires additional imaging for an enlarging circumscribed mass in the right upper outer quadrant. It is favored to be benign but further evaluation with additional views and targeted ultrasound is recommended.”

• BIRADS 0

CASE 1

DX: INVASIVE DUCTAL CARCINOMA

DISCUSSION FROM CASE 1

• What were potential pitfalls?

• Slow interval growth is hard to recognize

• Slow interval growth not as worrisome as rapid interval growth

• Potential to assume UOQ masses are intramammary nodes

DISCUSSION FROM CASE 1

• What can we do to help?

• Compare to remote priors (ie. 2 years or more)

•  “Oldest mammogram in the bag”

• Remember not all UOQ masses are lymph nodes

• Consider using hanging protocol where multiple priors displayed side-by-side

CASE 2OBSP Screening MRI May 2012

CASE 2

• Asymmetric right retroareolar enhancement . This would not be amenable to MRI guided biopsy given the position. Suggest right subareolar magnification views and ultrasound for further evaluation.

•  If no suspicious features on magnification views/ultrasound, suggest clinical correlation and 6 month followup MRI could be performed.

CASE 2

Cluster of indeterminatecalcs in retroareolar region. Recommend stereo bx.

CASE 2

• Pathology result:

• Proliferative FCC with usual hyperplasia

• Microcalcifications seen

• CONCORDANT

CASE 2MRI February 2013

CASE 2MRI July 2013

CASE 2MRI July 2014

CASE 2MRI February 2015

CASE 2

• Right subareolar enhancement surrounding the postbiopsy clip is increased in prominence compared to remote previous.

• Suggest right mammogram, magnification views of the subareolar region and second look ultrasound.

•  If no suspicious findings, suggest 6 month followup MRI.

CASE 2

DX: INVASIVE DUCTAL CARCINOMA

CASE 2MRI February 2015MRI May 2012

DISCUSSION FROM CASE 2

• What were the potential pitalls?

• Difficult area to perform MRI biopsy on initial study

• Potential for discordance when MR findings biopised under different modality

• False reassurance because of biopsy clip location

• Failure to recognize or act on slow interval growth

DISCUSSION FROM CASE 2

• What can we do to help?

• Remember interval growth is a predictor of malignancy

• Do not be afraid to rebiopsy lesions that are growing, changing or that look suspicious

CASE 3Left MLO2015 Left CC

2015

CASE 3• Focal

asymmetry posterior central on the CC view, probably parenchyma

• Added views +/- US

Screening January 2013 Screening January 2015

CASE 3CC spot CC spot

CASE 3

• “Persistent left posterior asymmetry on the CC view which may have been present in 2013 and only partially imaged at that time due to far posterior location. No suspicious ultrasound findings. This is felt to likely represent parenchymal tissue and a 6 month follow up left breast mammogram can be performed to ensure stability.”

CASE 3Aug 2015

CASE 3Jan 2015 Aug 2015

Again seen only on the CC view, is an asymmetry in the posterior 3rd of the left breast. This appears denser than on the previous imaging. This was not seen on the previous ultrasound. Impression:

Asymmetry left breast for which additional mammographic views again suggested.

Biopsy may be required under stereotactic guidance but the need for biopsy will bedetermined after the additional views.

CASE 3

DX: INVASIVE DUCTAL CARCINOMA WITH LOBULAR GROWTH PATTERN

DISCUSSION FROM CASE 3

• What were the potential pitfalls?

•  Initial mammogram report may have biased reader

• Allowing ultrasound to ‘trump’ mammogram

• False reassurance because only seen well on 1 view

• Recommending 6 month follow up instead of stereotactic biopsy

• Not correlating initial ultrasound finding to mammogram

DISCUSSION FROM CASE 3

• What can we do to help?

• Try not to ‘over characterize’ lesions on screening

• Consider all modalities together when forming opinion

• Remember stereotactic biopsy for masses not seen on US

• Ensure sonographic findings ‘fit’ with the mammogram

• Low threshold to check diagnostic ultrasounds

CASE 4Preoperative evaluation known left breast cancer September 2012

CASE 4

“Solitary nonspecific lesion in right breast lower outer quadrant with time intensity curves similar to the cancer lesion seen on the left side but overall less maximum relative enhancement. We could attempt to localize the right breast nodule sonographically with a plan to biopsy it if we can identify it.”

CASE 4

• Second look ultrasound October 2012:

• “Enhancing nodule seen on the prior MRI scan was not identified on this examination. This could represent an incidental fibroadenoma. A MR guided biopsy could be attempted.”

• Right breast ultrasound December 2012:

• “Targeted right breast ultrasound lower outer quadrant was performed. There is a 4 mm cyst at 6:00. No other abnormality is seen.”

CASE 4MRI Feb 2013

CASE 4MRI Feb 2013MRI Sept 2012

Patient started chemotherapy October 2012

CASE 4

• MRI March 2014:

•  Interval growth of solitary nodule right lower outer quadrant with interval development of increased signal intensity on theT2-weighted imaging. These are both worrisome findings, particularly given that the patient has had chemotherapy during this time interval which one would expect to impact any neoplastic lesion.

• Second-look right breast ultrasound April 2014:

• No correlate for MRI lesion

CASE 4

DX: DCIS with no invasion

MRI May 2014 Ultrasound May 2014

CASE 4Pre-operative MRISept 2012

MRI during chemotherapyFeb 2013

MRI post chemotherapyApril 2014

DISCUSSION FROM CASE 4

• What were the potential pitfalls?

• Not recommending MRI biopsy more strongly on pre-operative report

• Not recommending MR biopsy when no US correlate seen

• Not recognizing disappearance of lesion as potentially worrisome finding

DISCUSSION FROM CASE 4

• What can we do to help?

• Ensure each breast MRI centre has biopsy capability

• Better coordination between sites when MR biopsy is not available

• Remember malignant lesions may become less apparent or disappear on treatment

CASE 5

Which one is the cancer? Red or yellow?

Screening MRI May 2013

CASE 5Screening MRI May 2013

Screening MRI May 2014

Screening MRI May 2014

Now which one is the cancer?

CASE 5

DX: INVASIVE DUCT CA

DISCUSSION FROM CASE 5

• What were the potential pitfalls?

• Not finding the cancer on the first study

• Underestimating small focus with washout

• What can we do to help?

• Biopsy both lesions on initial study

• Biopsy all foci that washout

DISCUSSION FROM CASE 5

• Screening MRI is a screening study

• Goal is to identify findings suspicious for malignancy

• Balance between detection and over intervention

• Interval growth is a predictor of malignancy

CASE 6

Right Magnification ViewsAugust 2014

Right Magnification ViewsAugust 2014

CASE 6

“The right central breast shows predominantly linear calcifications that show branching and extend over a distance of approximately 4 cm.”

CASE 6Stereotactic guided core needle biopsy 8/22/14

Pathology: Benign breast tissue. Rare calcifications are identified. See full pathology report.

Result is concordant. Recommend 6 month follow up right breast mammogram with magnification views of the biopsy site.

Right Breast Specimen RadiographAugust 2014

CASE 6

6 month follow up post biopsy:

Right breast central biopsied calcifications have a slightly different configuration, likely due to interval biopsy, but do not appear increased compared to previous.

Follow-up bilateral mammogram in 6 months with right magnification views recommended.

Right magnification viewsFeb 2015

CASE 6Right magnification viewsAug 2015

Right magnification viewsAug 2014

Increasing suspicious right breast calcifications at the previously biopsied site. A repeat biopsy is recommended, with vacuum assistance.

DX: Ductal Carcinoma in Situ

DISCUSSION FROM CASE 6

• What were the potential pitfalls?

• Undersampling

• Calling suspicious calcifications concordant with benign result

• Few calcifications on specimen but not rebiopsied

• Not recommending re-biopsy on first follow up

DISCUSSION FROM CASE 6

• What can we do to help?

• Careful re-evaluation of images and level of suspicion for concordance

• Do not be afraid to re-biopsy if there is interval change

• Consider vacuum biopsy when diagnosis is unclear/discordant or calcifications may be challenging to target

CASE 7Right mammogramJuly 2015

CASE 7Last Friday April 15

CASE 7

DX: INVASIVE DUCTAL CARCINOMA

DISCUSSION FROM CASE 7

• What were the potential pitfalls?

• Edge of the film abnormality

• Unable to position breast properly because of tethering from cancer

DISCUSSION FROM CASE 7

• What can we do to help?

• Routinely assess positioning of breast

• Tech sheet where it should be noted if positioning was challenging

• Routine search pattern (including blocking, magnification) to ensure each area of film is examined

SUMMARY OF KEY POINTS

•  Interval growth is an important predictor of malignancy

• All breast imaging modalities should be integrated when formulating opinion

• When there is interval change in a lesion, re-biopsy may be required

• Role of screening is to detect findings suspicious for cancer not necessarily to detect every cancer at earliest stage

• Remember to check technique and edge of films

IN CONCLUSION

“No matter what measures are taken, doctors will sometimes falter, and it isn’t reasonable to ask that we achieve perfection. What is reasonable is to ask that we never cease to aim for it.”

wDr. Atul Gawande