0:01

Now that we've seen some really great examples of

0:05

BI-RADS 3 on mammography, I just want to summarize

0:08

what we've talked about and kind of go over some

0:09

of the data that supports these indications.

0:14

So the first indication is a non-calcified round

0:18

or oval circumscribed solid mass that has not

0:21

been shown to be stable for at least two years.

0:27

As we show, those spot compression views can be

0:29

really helpful to disperse adjacent fibroglandular

0:33

tissue so that we can visualize the margins.

0:36

We really want to be sure that the

0:38

margin is circumscribed, and those spot

0:40

compression views are very helpful for this.

0:44

When we see a circumscribed mass on mammography,

0:49

we will do a targeted ultrasound, and that's

0:52

helpful because sometimes these masses represent

0:55

a simple cyst or another benign etiology that

0:58

we would be able to assess as a BI-RADS 2.

1:00

So we really want to reserve the

1:01

BI-RADS 3 for findings that don't have

1:04

a definite benign sonographic correlate.

1:08

The next finding is a focal asymmetry,

1:11

and there's strong data in the

1:12

literature that there's between a 0.5

1:14

and 1% likelihood of malignancy for a

1:17

solitary focal asymmetry identified at screening.

1:22

So just a few things to note are that it has

1:24

to meet criteria for a focal asymmetry,

1:26

and that means that it should be a two-view finding

1:30

occupying less than one quarter of the breast.

1:33

And there should be a full diagnostic evaluation.

1:36

So we want to make sure we're doing spot

1:38

compression views and not giving this

1:41

assessment right from a screening mammogram.

1:45

It's important that the asymmetry is not associated

1:47

with any distortion, microcalcifications, or a mass.

1:51

We want to make sure we're differentiating

1:53

what a stable focal asymmetry is.

1:56

So if we have prior exams and we know that that

1:59

asymmetry has been present for greater than two

2:01

years, that have a malignancy rate of 0%.

2:03

That would just be considered part of

2:05

that patient's normal fibroglandular

2:08

tissue versus a developing asymmetry.

2:11

And that's a new or increasing two-view asymmetry.

2:17

And it's been shown that even without an

2:19

ultrasound correlate, a developing asymmetry

2:21

can have a malignancy rate up to 20%.

2:23

So it...

2:24

developing asymmetry really

2:25

should be given a BI-RADS 4.

2:27

So when we talk about BI-RADS 3 for a focal

2:31

asymmetry, we're talking about a focal asymmetry

2:34

seen on a baseline screening mammogram.

2:38

And we know that that has a very low

2:40

but non-zero chance of a malignancy.

2:44

That final indication is an isolated

2:49

when we don't have prior examinations available.

2:52

And like I've shown, we need to have magnification

2:55

views before making the final assessment because

2:57

those allow us to really see the morphology

3:00

and the distribution of the calcifications.

3:04

The BI-RADS 3 category should only

3:06

be used for punctate calcifications.

3:10

And we want to differentiate punctate from

3:12

either round or amorphous calcifications.

3:15

So punctate are very small,

3:21

Round calcifications are larger than 0.5 millimeters.

3:26

And usually, those can be assessed as benign.

3:28

I think in practice, we often will see mixed round

3:31

and punctate calcifications, and we can consider

3:34

that a BI-RADS 3, but if they're all larger than

3:38

0.5 millimeters, then those can be assessed as benign.

3:44

Amorphous calcifications are when they

3:46

have a fuzzy or smudgy appearance.

3:49

And those should be assessed as suspicious,

3:51

and the magnification views are very important

3:54

at differentiating the round punctate morphology,

3:58

which are probably benign or benign, from amorphous,

4:02

which are suspicious and should be biopsied.

4:07

We also want to make sure we're

4:08

evaluating really carefully

4:11

the distribution of the calcifications and

4:13

making sure that the finding we're giving

4:15

a BI-RADS 3 is really an isolated group.

4:18

If they are in a diffuse pattern or there are

4:21

multiple groups all over the breast, then we

4:23

can assess those calcifications as benign.

4:26

If they are in a linear or a segmental distribution,

4:30

then we want to assess them as suspicious and biopsy.

4:37

Now the BI-RADS Atlas gives a few other examples

4:40

of findings on mammography that may be appropriate

4:45

for a BI-RADS 3 based on radiologist discretion.

4:49

There's not strong data to support these.

4:52

The first is calcifications thought

4:54

to be developing fat necrosis.

4:56

And we showed an example of that.

4:59

Second is calcifications that are thought to

5:01

be vascular on the full diagnostic workup.

5:05

It's, you think they're probably vascular,

5:07

but you can't tell with a hundred percent

5:09

certainty. Hopefully in six months, that

5:12

will declare itself and you'd be able to

5:14

better determine that those are for

5:15

sure vascular calcifications and not

5:17

linear suspicious calcifications.

5:24

The third one is an asymmetry or a distortion

5:26

that's thought to be a post-surgical scar.

5:30

I know in our group, we do this very infrequently.

5:33

We try to use scar markers and really try to

5:36

determine at the time of the diagnostic workup,

5:38

whether this is related to a prior surgery.

5:42

And if we can't do that with confidence, then we

5:44

would want to do a biopsy because we know, especially

5:47

distortion has a high chance of malignancy, but the

5:51

BI-RADS Atlas does say if you think it's probably post

5:53

surgical scar, but without 100 percent certainty,

5:56

that might be a reasonable BI-RADS 3 indication.

6:02

And then finally, you know, we talk a lot

6:04

about these being on a baseline exam or one

6:07

where we don't have two years of stability.

6:09

And there are some cases where it's

6:11

hard to determine stability given

6:13

differences in technique between studies.

6:15

Sometimes this is just patient

6:17

positioning between studies.

6:19

Maybe a patient has lost weight, has had an

6:22

interval surgery, like a breast reduction;

6:25

it's really hard to tell if something is newer or stable.

6:29

Another example would be when this is a first

6:31

study with digital breast tomosynthesis.

6:33

So if all of the priors were 2D mammograms,

6:36

this is kind of like a new baseline

6:38

and, and a finding may look different.

6:40

And that could be

6:41

a reason to put something into a BI-RADS 3

6:43

category that you might otherwise want to biopsy.

6:49

And just talking about, you know, I mentioned digital

6:52

breast tomosynthesis, and I think it's relevant to just

6:55

spend a minute on it when we're talking about BI-RADS 3.

6:59

So digital breast tomosynthesis is

7:01

kind of known as 3D mammography.

7:04

It's actually reconstructed images that allows us

7:07

to scroll through slices of the breast, and this

7:11

has been shown in numerous studies to decrease our

7:15

recall rates and increase our cancer detection rates.

7:19

There's also been some studies showing that

7:23

digital breast tomosynthesis leads to a decreased

7:27

BI-RADS 3 rate, and that's mainly due to being

7:31

able to assess focal asymmetries as overlapping

7:34

fibroglandular tissue when we're scrolling through the

7:39

tomosynthesis images and able to put a lot of those

7:43

focal asymmetries into a BI-RADS 2 category

7:47

and overall decrease our BI-RADS 3 rates.