Breast Ultrasound Workshop: Pitfalls - HD

Introduction and Disclosures

Good morning.

I promise there won't be too many mammograms during this talk, but there will be a few.

Here's my required disclosure statement. I have no disclosures and I'm gonna be talking about pitfalls and breast ultrasound today.

Objectives

These are my objectives for this talk. I hope by the end of it you'll be able to describe some specific pitfalls in breast ultrasound as well as what to look for sonographic and as well as a few mammographic features to avoid either missing malignancy or recommending unneeded biopsies.

I also hope that you just enjoy looking at lots of good hopefully ultrasound cases.

Broad Categories of Pitfalls in Breast Imaging

Basically when I think about pitfalls in breast imaging, I think of two broad categories. Basically mistaking a malignancy for a benign finding or missing a cancer or recommending unnecessary biopsies that could be safely avoided.

There's a third subcategory which can actually lead to either of the two main categories, which is inappropriate or failure to carefully correlate mammographic and sonographic appearance.

I'll be showing some case examples, four different types as well as multiple companion cases for each of them. I'll start with a benign appearing malignancy and go over some more examples of that as well as complex cystic and solid masses as I think these can be quite difficult. The typically benign hyperechoic mass occasionally is not benign. And also I'll be showing some cases of correlation between mammography and ultrasound.

Pitfall 1: Benign Appearing Malignancy

Starting with a first pitfall case, this is a benign appearing malignancy. I've already given away the answer.

This is a 61-year-old woman had a new mass on her screening mammogram. And you can see here the mass does have several benign features. It's oval in shape, it's fairly well circumscribed, especially up here, but maybe not so much here. There was no detectable blood flow and there are some posterior acoustic enhancement. This is also parallel in orientation relative to the skin.

And here's a clip of this mass and I think you can appreciate better on this clip that the margins are really not circumscribed in this area. There's these kind of focal out pouching areas as well as indistinct margins. There's also a second lesion here.

This is the mammographic image and it shows again that there are some areas of the margin that are more angular and indistinct and this is also denser than the normal breast parenchyma.

And this turned out to be a high grade ERPR negative, HER two positive invasive ductal carcinoma.

Teaching Points

Some teaching points before we move on to the companion cases. Obviously as in this case high grade invasive ductal carcinoma often will have some benign features. It can be round or oval in shape and occasionally be so nearly anechoic that may appear to be a complicated cyst and occasionally even a simple cyst.

And in fact, one study referenced down here showed that over 75% of high grade carcinomas demonstrated posterior acoustic enhancement, which is typically associated with cystic lesions versus 8% of the low grade tumors.

So this often benign finding of posterior acoustic enhancement can actually indicate a more aggressive tumor type.

Just to quickly review the benign features of breast masses at ultrasound is oval shape circumscribed margin parallel to the skin surface mildly hypoechoic and that's relative to fat hyperechoic which is also relative to fat. And as I mentioned, we're gonna talk about hyperechoic masses in case three, no posterior acoustic features or posterior acoustic enhancement also is in this case.

I just wanted to quickly review a few other primary breast malignancies that can appear benign at ultrasound. So we've already talked about the high grade invasive ductal carcinomas, but there are some more rare subtypes of invasive ductal carcinoma that can also appear benign including mucinous, medullary and papillary. And I will be showing some examples of mucinous and papillary carcinomas as well as very rare adenoid cystic carcinoma which is more often seen in salivary glands.

And then phyllodes tumors which are most often benign but can behave aggressively and also be malignant and metastasized. And I'll go over an example of those later.

It's important to remember that the most suspicious finding that you see either by ultrasound or mammography is going to determine your final birads assessment and the need for biopsy often as I hope you'll see in the next several cases, this is the key is in the margins.

So carefully evaluate the margins even if most of the margins appear well circumscribed as if there's even one small area that is not well circumscribed, including angular microlobular or indistinct. This should prompt biopsy and this may be the only suspicious finding that you have.

Internal blood flow is helpful when it's present, but if it's not present it's not terribly helpful because it does not mean that there is no internal vascularity and it does not mean that it's a cyst. And I have several cases of that as well.

Companion Case 1

This is the first companion case here. You can see this is our primary case up here and this is the case here. This looks very similar. It's oval parallel hypoechoic posterior acoustic shadowing. And here's the clip through it. You can see there's also a second lesion here and kind of a septation there.

And this turned out to be a fibroadenoma and this patient actually had several fibroadenomas.

Here's another fibroadenoma. This is actually what brought her in. It was palpable but we had an old mammogram and these were actually decreasing in size and this one had developed these typical benign popcorn like calcifications. And you can see here's the mass with calcifications, the fibroadenoma. And this was the fibroadenoma I showed on the prior slide.

Companion Case 2

And here's another companion case. So this was a 52-year-old woman with a new palpable mass here you can see here it's overlying the pecs but has really well circumscribed margins. It's oval and on ultrasound, it also has many benign features, well circumscribed margins, posterior acoustic enhancement, it's oval and parallel.

Lucky for us this case did have internal vascularity and was biopsied and shown to be a mucinous invasive ductal carcinoma.

And here's the clip, just showing those features very well circumscribed posterior acoustic enhancement.

Companion Case 3

And this is just a kind of acute companion case. This is just showing here there was no internal vascularity. I think here you can see these actually look quite similar to each other. This is an actually round, which is typically a little bit more suspicious, than an oval shape. And we aspirated this and it completely went away and was consistent with a complicated cyst.

Companion Case 4

So another companion case here. This was a mass that was found on Abus. This is a coronal reformat of an ABIs exam. This marks the nipple and this actually shows where this is in the upper upper quadrant of the left breast. I just did a photographic zoom here you can see this is hypoechoic. And actually here the margins look pretty indistinct, but at handheld ultrasound the margins looked for the most part very well circumscribed.

Again, we have an oval mass parallel, almost very hypoechoic, almost anechoic with posterior acoustic enhancement and no internal vascularity. And I saw this and interpreted it as a abus only or screening breast ultrasound only finding it met all the criteria as far as I could see for birads three.

In retrospect you could wonder if this margin's actually a little bit angular. You can note here the size, you know where this is going. 0.76 centimeters. She did come back in six months luckily and it had grown to just under a centimeter. And you can see I think the margins look a little more indistinct here. And this was biopsied, six months later and shown to be a high grade invasive ductal carcinoma.

Companion Case 5

Another companion case. This will be the final companion case for pitfall one. This is an another patient with a palpable mass. You can see the BB here mostly circumscribed margins may be a little indistinct or obscured here, but at ultrasound I think it's clear you've got these circumscribed margins, but you definitely have some angular indistinct margins over here.

And this did have internal vascularity and you can also see this has some cystic change and this turned out to be a papillary carcinoma. And here's the clip I think on the clip you can really appreciate that those margins are not completely well circumscribed.

Pitfall 2: Complex Cystic and Solid Masses

And this leads nicely into pitfall case number two, complex cystic and solid mass is the, that prior case would be a, a solid mass with cysts in it.

So pitfall case two here, another new mass seen mammographically and this is what we see at ultrasound. Many benign features, again, posterior acoustic enhancement, parallel over oval and shape very well circumscribed margins, no internal vascularity was identified. And here's the clip showing those margins as far as we can see look really nice and circumscribed.

There are clearly anechoic components but there are also these hypoechoic areas as well and it's hard to know are those solid? Is that just debris and some cysts? Well this turned out to be just cyst wall and apocrine metaplasia completely benign.

Definition and Characteristics

So birads defines complex cystic and solid mass as a mass that has anechoic fluid or cystic components as we just saw. And echogenic or solid components, this includes cysts with thick walls and they define thick as zero, 0.5 millimeters or greater thick septations or solid intracystic or mural components. It also includes solid masses with cystic spaces. As you recall, that was the last companion case we saw.

Clustered microcysts are benign and can be difficult if not impossible to distinguish from complex cystic and solid masses. And sometimes you just have to biopsy a clustered microcyst to prove it. These will consist of small anechoic cysts with thin septations without discrete solid components.

It's important to note that these can't ha these can have microlobulated margins and that's due to the fact that it's, it's created by small cysts and the walls of those small cyst, kinda like a cluster of grapes may have a lobular margin, microlobular margin and there should be no internal vascularity.

So complex cystic and solid masses are fairly uncommon. However, more than a third of them can be malignant when they are malignant. They can be a high grade invasive ductal carcinoma and the cystic spaces will represent necrosis in that case. And they may also be papillary lesions. They could be benign papilloma, atypical papilloma papillary DCIS or papillary carcinoma.

Companion Case 1

So I have several companion cases for this. So this was a another new circumscribed round mammographic mass and at ultrasound we see a fairly well circumscribed, but again not completely, nearly anechoic mass with all these irregular looking septations and mural nodularity, no internal vascularity could be appreciated. And this turned out to be a high grade ductal carcinoma in situ.

You and I think on the clip here, you can really see those nodular irregular mural components and thick septations and you can also again appreciate the margin is not completely circumscribed and again has these kind of outpouching areas and angular and indistinct areas.

Companion Case 2

This is another companion case, another coronal reformat from an abus. And I think this shows really nicely in this case the margins are not circumscribed. You can see these angular margins here which show up nicely in the handheld here. And in contrast, look at these margins, these angular areas versus this really nice circumscribed margin of the primary case.

Again, there are no internal vascularity could be appreciated. The other point I wanted to make is if you ignore the margins, actually the internal characteristics of these are almost identical. The clincher here really is the margins and this turned out to be a papillary carcinoma.

And here's the clip again, the theme here is the clip shows the margins really well. Again, this one has posterior acoustic enhancement because of the cystic components likely.

Companion Case 3

And the final case, final companion case for two is this clustered. This is a clustered microcyst so this is entirely cystic with these nice thin echogenic walls. There's some intervening breast tissue. There was no vascularity as you can see here and here's the clip. But I do think it can be very difficult to distinguish is that just intervening breast tissue in there or are there solid components? And I don't think anyone would fault you for doing a biopsy of this.

Pitfall 3: Typically Benign Hyperechoic Mass

So moving on to case three, hyperechoic mass. So this is a 66-year-old woman with a new palpable left breast mass. Her mammogram was negative but she was heterogeneously dense and this was what was seen at ultrasound. We have this hyperechoic mass here. There was internal vascularity, somewhat indistinct margins, which you can see better here on the clip. Just really can't trace some of those margins out.

So this was biopsied and it was an angiolipoma.

So these are unusual benign tumors that occasionally can be seen in the breast. They're usually circumscribed iso to hyperechoic masses relative to the fat. With internal vascularity they can be visible mammographically and appears a solid mass or focal asymmetry. And the imaging appearances nonspecific and usually biopsy is required especially if they're presenting with a palpable mass or a new finding.

Hyperechoic masses are more echogenic compared to fat and equal in echogenicity compared to fibroglandular tissue which can make them difficult to see. As I'll show in one of the companion cases, fewer than 10% of breast masses are hyperechoic at ultrasound and they're almost always benign when you see them.

In fact, at least what I learned when I was a resident, if it's echogenic you don't need to biopsy. It's benign but that is not exactly true. Less than 1% of malignant breast lesions are echogenic. So it's really important in these cases if an echogenic mass to assess for any suspicious features that you might see at ultrasound or mammography to avoid missing the rare echogenic malignancy.

And of course the clinical scenario of a new or enlarging palpable mass is also very important as I will show.

And just to review, what are suspicious features of breast masses at ultrasound And that includes a regular shape, non circumscribed margins, non-parallel orientation, posterior acoustic shadowing, associated architectural distortion. And again it's very important to correlate with a mammographic appearance And clinical history as well as I discussed.

And this is really important with echogenic masses because hematoma or fat necrosis or infection can present as some as an ill-defined echogenic area so it can appear suspicious, but in the appropriate clinical scenario you can safely follow these lesions to make sure they resolve. And I have a few examples of those.

Companion Case 1

So starting with the first companion case, this is an enlarged, this patient presented with an enlarging palpable mass. She had actually, been in our clinic one to two months earlier, had a negative mammogram and negative ultrasound and she came back and said this area is still growing and this is the, still image of the area of palpable concern.

And I think this shows up pretty well on the clip, but I'm gonna point out that here's the normal looking normal echogenic breast tissue which gets disrupted by this irregular mass that is this pretty much the same echogenicity as the adjacent breast tissue. And here's the color image demonstrating there is quite a bit of vascularity in there. It actually brings out some of the posterior acoustic shadowing present and this turned out to be an invasive lobular carcinoma.

And here's the clip I think, I hope that you can see we kind of come out of the mass and there's more normal breast tissue there, right there. And as we go in you can see it kind of going up into the fat and how irregular it is.

And this is a mammogram. I don't think this is visible mammographically. Here's the 2009 exam and then the 2014 exam when she was diagnosed and it just looks like breast tissue, unfortunately she already had an enlarged lymph node with lymph node metastases at this time.

And here's the MRI showing this large area of non mass enhancement, typical of invasive lobular carcinoma.

Companion Case 2

Pitfall three, companion case. This patient presented with a actually for her screening mammogram, she had a bruise, marked by the technologist with these mole markers. And you can see right in here there's this kind of a vague new, asymmetry. And this is the appearance at ultrasound. There was anechoic area centrally with this somewhat ill-defined hyperechoic area right in the area of her bruising.

We brought her back two months later and this had almost completely resolved. It's actually really nice that that little cystic area had collapsed and made us feel comfortable that we were looking at exactly the right place and that was consistent with the hematoma. And here's the image, here's the clip, just showing some more features of that.

Companion Case 3

So this is another echogenic mass. This patient presented with a palpable mass in her axilla. It was so far away and difficult to get to, we couldn't see it on the mammogram. So we did an ultrasound and you can see there's this mixed echogenicity mass with hyperechoic and hypoechoic components. And this turned out to be a benign phyllodes.

Companion Case 4

And just to, this is a really a companion case of the prior companion case. This was a biopsy proven fibroadenoma in 2014. You can see it looks like a pretty typical fibroadenoma. Interestingly, she came back less than a year later in 2015 with a rapidly enlarging mass. And this actually, came back as a malignant phyllodes. So it was probably a fibroadenoma that had a phyllodes component in it that just took off and became a malignant phyllodes.

Pitfall 4: Failure to Carefully Correlate with Mammogram

So, okay, so finally I'll start with, I'll end with failure to carefully correlate with a mammogram. So we have a 62-year-old woman. This is a solid mass detected on a baseline ultrasound screening exam. This is the handheld image showing this almost anechoic oval parallel, circumscribed mass with a little echogenic focus suggesting a calcification and a biopsy was recommended and performed and unfortunately we didn't pay too much attention to the mr the, mammogram.

So this was 2009, this was from five years earlier. And you can see there's this mass you can barely see, but there's some course calcifications here. And this was the 2016 image. You can see the clip from the biopsy right next to that same course calcification the mass you can't see it's obscured here. And this turned out to be a fibroadenoma.

And the point here is to very carefully correlate with your mammogram. So we could have avoided this biopsy if we saw, oh there's a, there's a mass there. It's been at least stable for seven years, has calcifications in it. We see a calcification in this mass is the fibroadenoma, we don't need to biopsy it.

On the flip side, if you do good correlation with the mammogram, you may find some very subtle, suspicious, findings on the mammogram and something that otherwise looks benign and would prompt a biopsy appropriately to diagnose a cancer.

Companion Case 1

Here's another companion case. So this is another abus. There's the bb, the, I'm sorry, the marker for the nipple. Here's the mass here and this is what it looks like on handheld. You can see this is again parallel circumscribed oval and it's actually isoechoic to fat and it's standing out here because it's surrounded by echogenic, more echogenic breast parenchyma.

And again, this time we did correlate with the mammogram. This is the tomosynthesis and you can see this completely lucent mass which correlated to the same location as this. And this is consistent with a lipoma. And here's the clip showing all benign features and the key here is it's really isoechoic to the pre mammary fat up there.

Companion Case 2

Another case, that showed really nice correlation with mammogram here. So I hope this projects, but you can see this really nice thin pseudo capsule with some fat on the other side of it. And then material that's basically iso dense to the breast parenchyma. This is that breast within a breast appearance. And this is, a pretty typical appearance of a hamartoma at ultrasound that can be quite variable in their appearance because hamartomas are made up of basically breast parenchyma and fat. And depending upon the composition will affect how it looks. But this is a typical finding on the mammogram and makes us feel confident that this is just a hamartoma.

And here's the clip again showing this has many benign features. It's circumscribed oval parallel and made up of mixed hypoechoic to hyperechoic components. Typical of a hamartoma.

Companion Case 3

So this is another mixed echogenic mass. You can see this has a lot of internal vascularity in the echogenic components. And here's the clip just showing this peripheral echogenic component. If it weren't for that vascularity, I think this could look a lot like a hematoma.

Here's the mammogram showing this is a very dense mass. It is palpable. There's actually a second mass here, you can just see on the edge of the clip here. And this turned out to be a B-cell lymphoma.

Companion Case 4

And I think this is the last companion case of the series here. I just put this in here because I think it looks almost identical to the case. I just showed very dense mammographic mass. This woman presented with a bruising history of trauma and this looks like a typical hematoma. There was no internal vascularity and this completely resolved on follow-up. So we did not biopsy this, we just had her come back.

Conclusion

So if you remember, nothing else from this talk malignancies can have benign features at ultrasound. Very important to assess the margin. That will often be the key finding even with many other benign features. And also to look for vascularity. It's helpful if it's present, not terribly helpful. If it's not complex.

Cystic and solid masses versus clustered microcysts and complicated cysts can be very difficult to distinguish. Remember that about a third or more complex cystic and solid masses can be malignant. So if you just can't tell and you think there might be a solid component due to the biopsy and then remember to correlate with the mammogram, this can help you avoid unnecessary biopsies and also avoid missing subtle, suspicious features and otherwise benign appearing malignancy.

Thank you.