The Myometrium - HD

Imaging the Myometrium

We're gonna speak about the myometrium this morning. It's a little bit artificial. I was just saying to Beverly, because the next speaker has endometrium and it's kind of hard to split the organ, not even down the middle from the inha. Somebody gets the inside and somebody gets the outside.

For those of you who wanna hear about the outside of the uterus, we're gonna do the myometrium.

You can look at the uterus with the transabdominal approach. Of course, you need to have a full bladder for this. The thing to remember, which I remind my sonographers, I have no issues whatsoever. If a patient does not wanna do a transvaginal ultrasound, no problem. But you can't do a halfway job on the transabdominal view. They have to buy into the concept that you have to fill your bladder for the transabdominal.

We do sagittal and transverse images. A normal uterus is somewhere around 10 by five centimeters.

For the transvaginal approach, of course, you need the empty bladder. It's a little unfortunate when a patient attempts a transvaginal approach. She comes in, she empties her bladder, you try the trans vg, can't tolerate it. Now you gotta start from absolute zero of that bladder, but that's the way it goes.

Empty bladder, sagittal and coronal imaging plane. At this point, we take separate images of the cervix and a just a reminder, you'll see otan cysts all the time. We don't report them. They're of no significance.

Majority of patients will have an verted and inflexed uterus. Retroverted means the whole uterus is going backwards. Retroflexed means just the fundus is flexed posteriorly. And remember, of course, that the uterus in a healthy pelvis will move around. It'll go from verted to retroverted in some patients, and slide from side to side.

A few images.

Retroverted, these are old images, but we just don't do that many transabdominal images anymore. Here's a retroverted uterus. You can see the cervix anteriorly, and then the whole uterus heads posteriorly. And then the retroflex where the uterus is pretty straight, but there's a little rotation just at the fundus.

Here's the transvaginal image. Of course, everyone here is quite familiar with this. This is an verted uterus. You can see the normal myometrium, the thin endometrium, and I'll try not to say the word endometrium for the next half hour. And then a coronal image of the uterus here. And that little white line.

Postmenopausal Changes in the Uterus

Remember that the uterus changes its appearance in the postmenopausal patient. That uterus will atrophy. And of course, the size of the uterus is dependent on how many children the patient has had with each child. The uterus gets larger and larger, but certainly after menopause, the uterus will get smaller and smaller.

We also see that the peripheral veins dilate and the arcuate arteries may calcify. And these are located between the inner third and the outer one third. You particularly will see these calcifications in patients with diabetes, vascular disease, hypertension, hypercalcemia.

I have never mentioned them as part of my report because I consider them a normal appearance in a postmenopausal patient. But I have a younger colleague who was trained to always mention them and recommend that the patient be worked up for the presence of atherosclerotic disease.

That's another sort of opening the door to something very much entirely, but I still stick with it is by the time you see it, the information is not gonna change anything.

Here's what I'm talking about. These calcifications, you can see these sort of discreet echogenic foci, and these are just calcifications in those vessels. And notice how much smaller the uterus is. We can get the entire uterus, including the cervix, all on one image. And you can see that they're located in sort of that peripheral one third around the myometrium.

A video clip of the same thing. This patient has significantly more calcifications. It just gives you an outline almost of the size of the uterus.

Essure Devices

A few words about essu devices. These are something that we can see when we image the uterus. And the essu devices are irreversible form of contraception, and they are placed in the office with a scope into the interstitial portions of the fallopian tube on both sides. And they're very easy to see graphically.

However, you should be aware that there have been an increasing number of patient complaints with Essure devices, mostly related to pain, but also related to allergic reactions to the metal component of the device. There is now a black box warning on these devices in the United States, and their use has been suspended in the eu, and this is what they look like. And you can imagine something like that, sono graphically would be pretty easy to see.

This is what they look like on a transvaginal image. They start from the endometrial cavity and they run through the interstitial portion of the tube, and then they set out somewhere in the fallopian tube outside of the uterus. And you can see on this side, it doesn't quite reach the endometrium, but still fills the tube here.

And you can pick these up, transabdominally or transvaginally, and on the video clip, you see them go by on both sides.

Adenomyosis

All right, let's talk a little bit about adenomyosis. Adenomyosis occurs when the endometrial glands and stroma burrow into the myometrium. And you can think about it a little bit like endometriosis in the myometrium instead of outside of the uterus.

So you have the same sort of cyclical reaction of these endometrial cells, but it's occurring within the myometrium instead of in the endometrial cavity. It's typically seen in multiparous patients and older patients, but there is some discussion about whether it's just because we image older patients more often, and we don't image as many 20 year olds for these symptoms, because I think I feel like I see it, and I have seen it in patients as young as 21 or 22.

Most patients who have it are asymptomatic. However, this can be the source of pain or hemorrhage or uterine enlargement. It's very non-specific symptoms. And apparently up to 60% of the time, the patient can have both adenomyosis and fibroids.

So adenomyosis can be either focal or diffuse. The focal is a little bit more difficult to differentiate from a fibroid. What we see is focal areas of change in heterogeneity, either increased echogenicity or decreased echogenicity.

Very classic for adenomyosis is this Venetian blind appearance, which is the streaky shadowing that you get that look like Venetian blinds. If people still know what those are, I should have a picture of them.

You get very also very classic, which will help you with the diagnosis is the asymmetric thickening. So sometimes you don't even see anything going on in the myometrium, but you notice that the endometrium, instead of running right through the middle of the uterus, sits much farther to one side than the other.

And typically, adenomyosis happens more in the posterior aspect in the uterus. So the myometrium is shifted, the endometrium is shifted anteriorly. So watch where the endometrium is as you do your sagittal sweep.

The other thing that can happen very typically with adenomyosis is it gets very difficult to even see the endometrium. So if you feel like you're challenged about where to put your calipers to measure it, you need to start thinking about whether you have some underlying adenomyosis.

Another classic finding for adenomyosis is myometrial cysts. And these can be large or small, but they don't tend to be sitting right on top of the endometrium. They tend to be just a little bit deeper than the endometrium.

You can also see echogenic nodules, little, which are probably the cysts with debris inside them. And again, adenomyosis that's focal can be very difficult to tell from a fibroid.

Here's the asymmetry of the endometrial location. You could see the endometrium is up here. It's a multi-layered endometrium, but if you compare the anterior myometrial thickness to the posterior myometrial thickness, we clearly have asymmetry of the myometrium. This is also what helps create that globular shape, which is classically described in adenomyosis.

Here's the Venetian blind appearance. You can see these sort of vertical streaks coming off the back of the uterus. And then when we res up, we can see this patient also has myometrial cysts.

Here's a different patient, a closer image. You have to sort of slow down your scan. Sometimes this, when we go in the room with all of our transvaginal studies and we basically send the sonographer in, do the studies note when they're, we have video monitors that tell us what's going on in each of the rooms. And when you see they're getting to the leftover, hopefully you stand up from your desk, you go in, and then you'll get sort of the quick tour.

Unless you get a phone call or another patient or someone comes by or whatever. And then you see on the screen, Mary, Mary, Mary, Mary, Mary, Mary, Mary, Mary, and they're like, and then everyone in the room will be like, Mary, I think you're supposed to be in room three. And then you go running in.

But when you get in there, they're done, right? They've been in there, particularly if they've been waiting for you for a while. So they tend to go, here's the sag, here's the coronal, here's the right, here's the left. And you're like, okay, slow down, because you have to be looking at everything during that sweep.

You're watching the endometrium, you're watching the myometrium, you're looking for little cysts. So slow down your sweep and look really carefully if you're suspecting adenomyosis to try and pick up those little tiny cysts, which can be subtle, but once you spot them, you'll spot probably more than one.

Here's a patient where the myometrial cysts are not subtle. You can see these big cysts here, which are sort of not quite sub endometrial, but are almost clustered around the endometrium.

Then a corresponding HSG shows how those what really happens with those cysts. You put the contrast in and they each fill with contrast material. And you can imagine that without the contrast that these would all be black circles.

Here's a case given to me by Beryl, RAF who's speaking next, and when we sort of merged our talks, she didn't need this. She, because it is a myometrial slide. And so here you can see the little cysts right here. And on the inversion images, you can again see sort of the 3D rendered HSG now with the glands protruding into the myometrium.

Okay, here's a patient with a solitary cyst, kind of in the lower uterine segment. It sort of looks like fluid in a C-section scar, but she didn't have a C-section. And so then you're like, okay, is this a myometrial? Is this adenomyosis? Or what the heck is this?

So a little detective work, and the patient says, well, actually, I had a fibroid removed 20 years ago, and this is a fluid collection left behind in the site of the fibroid, which brings us to talking about fibroids.

Uterine Fibroids

It's hard to make fibroids interesting, but I'm gonna give it a try. The most common tumor of the uterus, 20 to 30% of women over the age of 30 higher in African American women. It's a benign, smooth muscle neoplasm.

We know it's estrogen dependent. We did look at these in our pregnant patients a few years ago, and it's remarkably difficult to do a study on what happens to fibroids during pregnancy because so many things can happen to fibroids and the uterus changes so much, and things switch locations that you think you're looking at the left mid body ute fibroid to measure, but then they come back eight weeks later and there's nothing in the left and there's something posterior and there's something anterior, and it's really hard to know which one you're exactly following.

But having said that, during pregnancy, about a third will grow, about a third will shrink, and a third will stay the same. And traditionally, we know that most fibroids will start to shrink after menopause.

So when you see perimenopausal patients who are coming in with abnormal bleeding and they have fibroids and they say, oh my God, I can't, the life is so bad and you think, oh, you just gotta stick it out till menopause, and then the fibroids hopefully will shrink.

So these are focal hypoechoic, well-defined lesions, which typically have some shadowing and certainly can deform the contour of the uterus. Depending on their size and their location, they may be calcified and they are frequently multiple.

So I'm more inclined to go with multiple fibroids than one fibroid and one adenoma. But again, they can be, there's a big overlap in their appearance.

Patients who have symptoms from their fibroids, it's typically related to the location of the fibroid and the size of the fibroid. A two centimeter intramural fibroid probably isn't gonna bother very many people, but a 10 centimeter fibroid that is on the lower anterior segment that's pushing on the bladder is gonna give you some symptoms.

So fibroids can be sono graphically identified or characterized as submucosal, intramural, or subserosal. Our gynecologists have actually asked us not to use that terminology anymore. The only thing they're really interested in is the impact on the endometrium. And if it's not, they say We're just not as good as we think we are at the intramural versus subserosal labeling.

Remember that fibroids can extend off of the uterus and grow into the broad ligament. They can hang off and be related to the back of the cervix. And patients who have fibroids who conceive are at increased risk for spontaneous abortion in the first trimester, and fibroids can certainly impair delivery. And they can also impact fetal growth depending on where they are in relationship to the placenta.

We also see in the patients who have fibroids that grow rapidly during pregnancy that they can necros or infarct and cause significant pain in those women.

So let's look at a couple. Here's an intramural fibroid. It's actually a couple in this patient. There's this one anteriorly and there's another one posteriorly, and the endometrium sort of squirrels right down there between them. But fibroids can obscure your evaluation of the endometrium, but we don't care about that.

Now here's another intramural fibroid. And the question is, you look here and you think, well, this certainly has a submucosal component because look at it, it's just right there deforming the endometrial stripe. And but during a sono histogram, you can see that the endometrium is actually intact completely over this, and it has deformed the endometrium, but it has not broken through. So this is not truly causing a submucosal fibroid.

Here's a submucosal fibroid where you can see on the clip that it has completely invaded and it's a little bit like in the old days, looking at barium enemas and seeing if you have an acute margin or a smooth margin on your colonic polyp. If over 50% of the fibroid is submucosal, the reproductive endocrinologist tell me they can get it out with a scope, but it has to have a significant submucosal component, and they have to have a good understanding of how far in the back half of that fibroid is.

Sono histogram can be very useful. You can see as we slowly inject fluid that we're completely outlining this lesion, which the differential would be, is it a polyp or is it a fibroid? But it is hypoechoic, it's heterogeneous, and it has these shadowing off the edges of it, so much more consistent with a submucosal fibroid than an endometrial polyp.

Here's another patient who came in with significant bleeding and you can see on the video clip that there is actually a big mass down in the lower uterine segment. And if you watch the mass, you can see that it actually has a stalk here and the stalk is starting somewhere up in the anterior myometrium. And when we put color flow on, you can see that the blood flow comes down the stock and into this large mass.

And this is the 3D rendered image, which is just the lower uterine segment. And this is the stalk. And here's the large fibroid that has prolapse right down into the cervical canal from the anterior myometrium.

Remember that the subserosal fibroids are often undulated. So when you see large masses in a patient who has lots of fibroids, the adnexal mass is probably gonna be a fibroid. There's no reason to really call in another differential diagnosis.

But the interesting thing about this case is this is a retroverted uterus. So here's the fundus of the uterus here, and here's this big classic appearing fibroid, which is pedunculated. But when we do the 3D rendered view, so you notice here that here's the uterus and the fibroid is clearly on the left side, it's down in the left cul-de-sac.

But when we do the 3D rendered view, because the uterus is retroverted, then have to move it 180 degrees or flip it 180 degrees so that you can look at it right side up. And when you do that, you rotate what was down in the left lower quadrant and it lands up in the right upper quadrant. So be careful when you're looking at a retroverted uterus on 3D imaging to make sure that you've got your rights and lefts in line.

Here's another patient that we've all seen. This is a 20 centimeter uterus. You're looking at this patient transabdominally. Is there any reason to do a transvaginal ultrasound in this case?

Well, if you haven't seen the ovaries, there's a possibility that the ovaries are way down low in the cul-de-sac and it's important to find them. So it is reasonable if you can't find them transabdominally to take a look, transvaginally.

So we did move to the transvaginal ultrasound, and you can see that this fibroid was measured as the largest fibroid, which is a six centimeter fibroid. But the issue is, if you look at the clip here, you can see what looks like a small uterus and a five centimeter fibroid right here. But here's the enormous fundal fibroid, which is not fully imaged transvaginally.

So when you have a 20 centimeter uterus, if you have something that you're seeing transabdominally, you've gotta trust that image. And remember when you're badging that you're gonna probably cut off quite a bit of the uterus. And your goal with the transvaginal ultrasound is not to get a more accurate depiction of the entire uterus, but again, to look for things that are down in the cul-de-sac, maybe see the endometrium a little bit better if it's displaced downwards and find a potential missing ovary.

Here's a classic lipoma. Sometimes the fibroids have quite a bit of fat in them, and we don't pursue that. We just read it out as a lipoma.

So fibroids can degenerate during pregnancy. They also can cause bleeding, and they also can cause compression of the bladder of the bowel or of the ureter.

So this is a very old case, but it demonstrates beautifully how this large fibroid broke down during pregnancy. This is the fetus over here, an amniotic fluid and a big cystic center in this fibroid, which was exquisitely painful for this patient.

Okay, what about this one? Well, this is a big cystic collection within the myometrium, and we know the patient has another fibroid over here. So is this a myometrial cyst from a degenerated fibroid or from adenomyosis? No idea. Not asymptomatic. We'll never know.

Here's another fibroid. This is almost a nine centimeter fibroid in at the uterus. And notice how half of it is echogenic and the other half of it is sort of streaky and hypoechoic based. And you can see the same thing here. This is the transvaginal look, very echogenic on one side, very hypoechoic and attenuating the sound on the other side.

So because of the unusual characteristics of this fibroid, the patient did undergo an MRI and because of the unusual characteristics on the MR, I'm sorry, I don't do MR so I can't tell you what they are, but some of you might know, the pathology on this lesion was benign.

Here's another patient who presented with a known fibroid, and this is another complication that can happen. You can see that this fibroid is entirely submucosal and we know that because it's outlined not bio aal histogram, but by all the blood from how actively she's bleeding. And she presented with massive hemorrhage and the submucosal fibroid was responsible and that blood not just was coming out transvaginally. So she was presenting with vaginal bleeding, but she's also bleeding into the cul-de-sac. And you can see she had a hemoperitoneum from the massive bleeding from the submucosal fibroid.

Another patient who had a normal GYN exam in the office. But no prior ultrasounds came in complaining of rectal pressure. And this is another thing that a fibroid can do. And you can see here's the uterine fundus here in the back of the cervix. And this patient had an 11 centimeter fibroid, which potentially had been growing fat quickly because of the areas of cystic necrosis in the center giving her rectal pressure. And because it was felt that everything was normal. One year earlier, she also went to surgery and pathology was benign.

Fibroids can show up in the cervix. This is a cervical fibroid path proven, but remember that there's a very similar looking mass in the cervix and in this patient the mass was high grade cervical carcinoma, so you probably need pathology on cervical lesions.

Here's another patient who presented 87 years old with postmenopausal bleeding. And on transvaginal sonography we could see a very large mass involving the cervix. Here's the fundus up here and the endometrial stripe, and it's a small postmenopausal uterus, but yet this three and a half centimeter solid mass. And on close exam we could see little bit of air and a little fluid tracking in as you move the probe in and out. And I was concerned that that could be a fistula into the rectum. But it turned out when this was resected that the patient had squamous cell carcinoma with central necrosis and not a fistula.

Another patient, 38 years old, treated for leukemia and in remission for three years after a bone marrow transplant who came in with new pain and bleeding and the similar appearance that here's the uterus up here. And there's this big mass, this big solid mass that has kind of taken over the cervix and expanded it. It's actually almost six centimeters with lots of blood flow and that turned out to be recurrent leukemia uterine.

Distinguishing Sarcomas from Fibroids

The thing everyone worries about is could any of these fibroids be sarcomas? So the classic teaching is that any mass that grows rapidly, you need to be thinking about a sarcoma. Also, though it probably is not a fibroid that's been there for years, that has changed into a sarcoma, it's probably a new mass, but they can have such overlap in sonographic appearances with fibroids. They're probably miscalled fibroids when they're small.

So remember think about this, when you have an unusual circumstance, when you have something that just shows up when you have something in a younger patient, when you have a rapidly growing mass in someone who doesn't have any other fibroids, these can be quite aggressive with a very poor prognosis. And remember that patients on tamoxifen are at increased risks for uterine sarcomas.

So again, in the perimenopausal or postmenopausal patient with rapidly growing masses, that's the wrong thing that's supposed to be happening to the uterus. Also, we've seen this in patients under the age of 25 who don't typically come in with 10 centimeter fibroids.

They're typically complex ultrasound is not sensitive or specific. If you have a concern, MRI can be quite useful, but often surgery is necessary.

So here's a 48-year-old who complained of bloating for three weeks, which is Mindboggling. She's a very thin woman and she has a 21 centimeter mass in her pelvis. But she said she only felt like she's been bloating for the past couple weeks. And this was, we did a transvaginal ultrasound because we really couldn't tell whether this was an ovarian lesion or an endometrial lesion, and we thought maybe we could find a little normal uterus tucked in somewhere or a couple normal ovaries, and that would help us give the surgeon some sort of concept.

But you can see on the transvaginal study that there was no normal anatomy there whatsoever. She did have an mr, which I think is quite dramatic, that shows you how large this mass was. It's well out of her pelvis. And again, three weeks of symptoms. And this turned out to be a MOC sarcoma.

Another patient, this is an old case, but demonstrates the change that can help you make the diagnosis. In June of 2003, this mass was 11.5 centimeters and read as a large solitary large fibroid. But she returned in November and the mass had gone to almost 14 centimeters and developed necrosis or cystic areas in the center. And so she went to surgery and this was also MOCs sarcoma and it was high grade and metastatic to the lungs by November.

Here's a 56-year-old patient who had a MOCs sarcoma, resected, diagnosed, and resected 18 months earlier, returned for a follow-up, again, feeling bloated. And you can see this massive recurrent tumor. No uterus or ovaries left just a massive tumor, which was a 27 centimeter recurrence.

Infections in the Uterus

Finishing up. The last thing I'm gonna talk about is infection in the uterus. And I'm crossing a line here because sometimes infection happens in the endometrium. But so endometritis is what we see postpartum. There are really no sonographic findings. You'll just notice that those patients have an enlarged uterus because they just delivered and they're quite tender on their uterus.

But ometria, this is when pus builds up in the center of the uterus, in the endometrial cavity, and we see complex fluid in the canal. And that typically is because there's no outlet to the fluid. Normally any fluid in the endometrial cavity should just pass out as a discharge or vaginal bleeding.

But patients with cervical stenosis following radiation or following trauma or following malignancy, can have any sort of outflow. Obstruction can have fluid buildup in the uterus.

So this is a 78-year-old patient who came in with an enlarged uterus, not bleeding, but enlarged on physical exam. And we notice that there's this irregular 14 millimeter thickening, very globular, blood flow in this tissue. And you can see that the rendered image almost gives you the sense of a duplicated cavity or a uterine septum with debris and complex fluid and mass like stuff on both sides. But this turned out to be omera and absolutely no tumor in there at all.

Miscellaneous Cases

The last case I wanna show is a patient who presented to us three months after a c-section with abnormal bleeding sent in for retained potential retained products. And she was found to have, so here's the sagittal image of the uterus, and you can see the stripe right here. Here's the external os, little nevo, the cyst, and this mass along the anterior aspect of the uterus hypoechoic.

If you, this is a little bit res up. It measured at least five centimeters. You can see it had almost like an echogenic line right down the middle of it. Absolutely avascular. The question is, is this a mass that has grown off the uterus or what could it possibly be?

She was said, let's get short term follow up. She came back, I saw her on her follow up exam and the obstetrician came down and she's like, I don't know, I did the C-section. She was totally fine. I can't, she, I don't think she even has bleeding. She's totally fine. What's going on here?

And I was like, you know this. I don't know if anybody knows what this is, but I was like, this doesn't look like a mass to me. This looks, it hasn't changed at all on the one month follow up. It's very smooth. It's very regular. I was like, what did you do when you were in there? What happened? So this is what she did. She put a piece of gel foam on the top of the C-section scar because she had a coagulopathy during the delivery.

Ooh, I just got peeped my time's up. Oh, well, sorry guys. Right? You'll never, so I know I'm getting beeped. It's like a fire alarm. But this is my last slide, but don't worry about it.

So here's the folded over piece of gel foam that I'm holding, and you can see that it's exactly the same look. And be aware that sometimes surgeons will put something in there and you just have to really talk to the physician and say, okay, what was in there? What did you inject? Did you put anything? Could this be a foreign body, which technically is a foreign body? And this will resorb over time.

So apparently my time is up. Thank you for your attention.