Dr. Kalesha Hack Sunnybrook Health Sciences Centre Division of

Mistakes We All Make:
Breast Imaging
Dr. Kalesha Hack
Sunnybrook Health Sciences Centre
Division of Women’s Imaging
Mistakes We All Make:
Breast Imaging
Dr. Kalesha Hack
Sunnybrook Health Sciences Centre
Division 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 1
RCC
2013
RMLO
2013
CASE 1
RCC
2012
RMLO
2012
CASE 1
RCC
2011
RMLO
2011
CASE 1
2013
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 2
OBSP 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 indeterminate
calcs in retroareolar region.
Recommend stereo bx.
CASE 2
• Pathology result:
•  Proliferative FCC
with usual
hyperplasia
•  Microcalcifications
seen
• CONCORDANT
CASE 2
MRI February 2013
CASE 2
MRI July 2013
CASE 2
MRI July 2014
CASE 2
MRI 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 2
MRI May 2012
MRI February 2015
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 3
Left MLO
2015
Left CC
2015
CASE 3
Screening January 2013
Screening January 2015
• Focal
asymmetry
posterior
central on the
CC view,
probably
parenchyma
• Added views
+/- US
CASE 3
CC 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 3
Aug 2015
CASE 3
Jan 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 be
determined 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 4
Preoperative 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 4
MRI Feb 2013
CASE 4
MRI Sept 2012
MRI Feb 2013
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
MRI May 2014
DX: DCIS with no invasion
Ultrasound May 2014
CASE 4
Pre-operative MRI
Sept 2012
MRI during chemotherapy
Feb 2013
MRI post chemotherapy
April 2014
DISCUSSION FROM CASE 4
• What were the potential pitfalls?
•  Not recommending MRI biopsy more strongly on preoperative 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
Screening MRI
May 2013
Which one is the cancer? Red or yellow?
CASE 5
Screening 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 Views
August 2014
Right Magnification Views
August 2014
CASE 6
“The right central breast shows predominantly linear
calcifications that show branching and extend over a distance
of approximately 4 cm.”
CASE 6
Right Breast Specimen Radiograph
August 2014
Stereotactic 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.
CASE 6
Right magnification views
Feb 2015
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.
CASE 6
Right magnification views
Aug 2015
Right magnification views
Aug 2014
DX: Ductal Carcinoma in Situ
Increasing suspicious right
breast calcifications at the
previously biopsied site. A
repeat biopsy is recommended,
with vacuum assistance.
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 7
Right mammogram
July 2015
CASE 7
Last 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.”
wDr. Atul Gawande