Hemorrhagic Cysts and Torsion Acute Female Pelvis - SD

Introduction

Hi, I am Deborah Rubins.
I do ultrasound at the University of Rochester.
And today I thought I'd bring you a talk on basically acute pelvic pain.
It's on hemorrhagic cysts and torsion and hopefully it'll help you better take care of your patients.
Welcome.
This would be an update for people on hemorrhagic CYS and torsion.
And our goals today are to certainly think about acute ovarian disorders.
Obviously I'm starting from the top.
The most urgent is rupture with hemoperitoneum.
And mostly today we're gonna be talking about the next two, which is torsion and hemorrhage.

So our objectives is to review the image appearance of hemorrhagic cysts and ovarian torsion.
And I want to introduce to you the SRU Consensus Conference guidelines that were published in 2010 for the management of hemorrhagic cyst.
And then we'll talk about some of the potential pitfalls in the diagnosis of hemorrhagic cys and ovarian torsion.

Review of the Normal Ovary

So just to begin, we need to review the normal ovary and remember that we're going to have developing follicles up to three centimeters in size.
And as the ovary goes through its normal function, we form a corpus lutetium.
And you can recognize that by this hypervascular rim.
It's thick walled and it has often cremated or infolding margins and it may or may not have internal echoes.
And this is a normal functioning follicle cyst that's gone through the physiologic menstrual cycle.

So again, what it looks like on CT as well as on ultrasound, this is not abnormal.
This is this hypervascular rim here on ct.
Same thing on ultrasound.
It has a low resistance flow and this cremated margin, these infolding edges that tell you that this is a normal corpus lutetium.
As I said, the internal echoes can be variable, so it can be relatively koic as you see over here, or it can be filled with internal echoes if there's been some hemorrhage, as the patient ovulates.
And as you might expect, the hemorrhage can have variable appearances as well.
It can be hypoechoic as you saw in the prior slide, but it can also be even echogenic.
And sometimes you can have a clot, which retracts, and again, this is a hemorrhagic echogenic corpus lium.
Notice that the patient does have some free fluid in the cul-de-sac indicating that she has recently ovulated.

Hemorrhagic Cysts

So what are hemorrhagic cysts?
Well, on ultrasound we define them as cysts with a thin regular wall, there's increased through transmission should be no internal vascularity.
And again, we can have variable patterns of internal echoes, which will change over time and ultimately resolve.
And basically this is something that's bigger than three centimeters that we see in the patient's ovaries as we do our transvaginal and transabdominal ultrasounds.

Internal Features of Hemorrhagic Cysts

So what are some of these internal features?
Well, these are the classic ones, a lace like or spiderweb septation, where you can see here these tiny, tiny, very, very thin dashes, which sometimes then can go all the way across, and can sort of fill in to be a little bit more solid looking.
We can also see a retractile or avascular clot.
And the clue to this is, again, you have straight margins or sometimes concave margins.
Here you can see a little bit of the fish net alongside of that clot here.
The cyst is mostly filled with the clot, but again, as it retracts, as it pulls back, it has these slightly cane concave and straight edged margins.
If you have a completely filled cystic structure as you see here with this increase through transmission, but it looks more solid, then you may need to watch it over time.
And as you can see, this is from Dr. Scout from La Gale University.
Over time this becomes more lace like and eventually has a small amount of this retractile crop clot with a straight edge against the sidewall.

Management of Hemorrhagic Cysts

So if you have a classic hemorrhagic cyst and it's under or equal to five centimeters in a premenopausal woman, you do not need to follow this up.
And the classic patterns are this fibrin strand pattern, this lace like reticular pattern or the retract clot.
If it's larger than five centimeters, then you should get a short interval follow up in six to twelve weeks to assure that it is actually resorbing.
And this was published from the SRU Consensus conference in radiology in 2010.
And I encourage you to take a look at this because it's very valuable in terms of following up your patients.

Hemorrhagic Cysts in Menopause

Can you have hemorrhagic cysts and early menopause?
Well, yes you can.
But you wanna make sure you describe them in your report.
And again, with these patients, this is no longer a normal physiologic function.
You wanna make sure that these resolve, so do get follow up on these patients in late menopause greater than five years after the last menstrual period.
Women do not ovulate, so they should not get hemorrhagic cysts.
And you wanna consider that these are neoplastic and manage them accordingly.

Pitfalls in Diagnosis of Hemorrhagic Cysts and Ovarian Torsion

The patients who are not classic, those are the ones who require more imaging.
So in those patients you wanna think about patients with low level echoes or a fishnet or a mesh appearance at slightly thicker appearance to that lace like pattern.
If you can't tell if it's a clot or a nodule, or if the echoes are layering, there are some things you may wanna consider.
So we'll go through those individually.

Diffuse Low Level Echoes

So here's a patient with diffuse low level echoes.
You can see here, is it one patient, this is a different patient.
Here is a third patient and these two on the left of your screen represented hemorrhagic cyst.
They resolved and went away on the right.
This is slightly more attenuating, although it's avascular and this did not go away.
This came out and this was a fibroma.
Again, diffuse low level echoes can all be hemorrhage, but they may not always be from a hemorrhagic cyst.
This patient here on the left of the screen was a hemorrhagic cyst on this one, you can see there's a slight bit of nodularity there.
You can see flow around the margin of this.
And this one was an endometrioma.
Another example of a patient with endometrioma.
Again, very, very diffuse, low level echoes here.
Did not go away.
She had a follow-up ct for another problem.
And this was incidentally noted, still present on her ct.

Fishnet Versus Mesh Appearance

So endometrioma, can we tell fishnet versus mesh?
Well here again, these fine lace like echoes here, they are over here, but if you look carefully, sometimes you'll see some abnormal contours here on the inside of the wall.
This is a mural nodule over here and this one and represents an endometrioma here, the MR for this patient.
On the right you can see the fat fluid level.
The fat certainly suppresses on the outer phase sequences.
So this one is a teratoma.

Clot Versus Tumor

What about clot versus tumor?
Well again, always turn on the doppler.
So here is an obvious nodular appearing soft tissue collection with some what looks like septations going out from it similar to this one.
But on this one you can see there's flow within this nodule.
This one had no flow and when it was followed, again this resolved over time was a retracting clot.
Again, always check for flow in the SEPTA and the nodule and follow up over time.
If there's any question.
And again thanks to Dr. Scout for this lovely case.

Layering Echoes

And layering echoes can occur in a hemorrhagic cyst, although we don't see them that often.
Here is such a case.
Here's another patient who has some layering echoes and this one happens to be an endometrioma.
So again, follow up is your clue.
If you can't tell the difference.

Other Pitfalls: Heterogeneous Echoes and Coexisting Conditions

What are some pitfalls we might encounter with hemorrhagic cysts?
Well, here's a patient who has heterogeneous internal echoes.
Here you can see the uterus here.
This was a young patient, so this is a transabdominal scan, normal ovary.
Here we can see that this looks like it should be a hemorrhagic cyst and actually it is a hemorrhagic cyst, but when you image the patient where she hurts, it's actually not over that cyst.
That's a little bit further down in the pelvis.
And you can see a funny looking mass here in the right lower quadrant, that when you measured it, it was 1.2 cm and you could almost make out a gut signature.
And when she was sent on to ct, you can see she has acute appendicitis with the appendix coming down into the pelvis, abutting this hemorrhagic cyst.
So always image where the patient hurts and beware that you can sometimes have more than one thing going on.

Hemorrhagic Cyst Versus Torsion

What about a hemorrhagic cyst versus torsion?
Certainly his cyst can act as a lead point for torsion.
And this patient had a mass seen on ct, was sent to ultrasound to see about torsion.
And when we actually imaged her, you can see all the echoes within this.
This was a hemorrhagic cyst.
We could not see any flow in this ovary.
So she was sent to the or, but it was only a hemorrhagic cyst compressing the normal ovary and we were unable to elicit flow.
This patient, however, on the other hand, is also with right lower quadrant pain, has an obvious retractile clot.
But it's certainly bigger than five centimeters.
She had a lot of pain, a lot of symptoms.
There was flow in the ovary.
However, the ovary was out of normal position, it was in the midline and so she did go to the OR and this was right ovarian torsion without ischemia.
So there is OV overlap.
And that does bring us to the next topic on our list, which is ovarian torsion.

Ovarian Torsion

As you know, this is partial or complete rotation of the ovarian vascular pedicle.
It can cause arterial venous or lymphatic obstruction.
It's most common in our reproductive age group and often has a large cyst or neoplasm as the lead point.
The most important probably is the clinical presentation, which is usually abrupt, pelvic pain, nausea and vomiting.

Gray Scale Features of Ovarian Torsion

So we have some gray scale features to look for and these are the most important, despite the fact that this is a vascular problem and the patient has symptoms because of vascular compromise, the gray scale is what tells us what's going on.
So we're looking for a midline enlarged ovary.
It can either be above the fundus or back in the cul-de-sac.
We'll see this string of pearls, these peripheral cysts, these displaced follicles, you can have a coexistent mass at least half of the time may see pre pelvic fluid and also look for the ovarian pedicle.
A target appearing mass, the twisted fallopian tube.

So let's go through these slowly here is an enlarged abnormal ovary and by enlarged I mean over five centimeters in length.
You can see the follicles are pushed peripherally and you can see echogenic stroma centrally midline position.
Very, very important.
So this is a patient you can see here is a transvaginal probe, sitting up against the uterus.
This ovary is in the midline, directly posterior to the uterus.
Again, these displaced follicles, very large ovary.
Here's another one from transverse imaging.
Again, uterus here and large midline ovary.
Abnormal in appearance, large size and large abnormal location.
Again, here's another patient.
We can see from the posterior aspect here, the uterus.
Here's an IUD in place.
Here is the ovary, again up in the midline and up anterior and above the uterus.

So the gray scale picture is classic here you can see here's a normal ovary again with the follicles displaced somewhat to the periphery.
But you can see normal flow certainly within the center.
And this ovary is normal in size.
Again, the TORS ovary has no flow, but it can also have damped flow or as we just saw in the prior case, look pretty normal looking flow.

Doppler Features of Ovarian Torsion

So what about these doppler features?
Well, if the flow is completely absent, that is considered diagnostic.
But if the arterial and or venous flow are present, that does not exclude the diagnosis of torsion.
And you can have arterial flow only or venous flow only.
And both of those can be present with torsion.
So we do wanna again look for a whirlpool sign, which will be twisted vessels in that vascular pedicle.

So just some examples of the various Doppler patterns.
Here's a patient with a three day history of left lower quadrant pain.
Not quite a classic history.
The left ovary however is larger than the right and the follicles are somewhat peripherally placed.
You can see normal flow in this right ovary, normal follicles, normal size ovary.
You don't see the same flow even with power doppler and absent flow, this is just noise above and below the baseline.
So this ovary unfortunately was infarcted at surgery.
She'd been obviously suffering for three days.

Here's a patient with a very very large cyst.
Again, you can see the normal side for comparison over here, the normal waveform.
But here is the abnormal enlarged gray scale appearance with these very small follicles, no normal follicles.
And even though you're seeing a doppler arterial and venous waveform, this is very abnormal.
It's damped compared to the normal side.
And you can see this big cyst which was the lead point.

So grayscale versus doppler, again, even though it's a torsion question, grayscale is by far the most specific with the appropriate clinical findings.
And in this recent review from from Vanderbilt, they found that over half were associated with a mass.
The ovary is always enlarged.
Most of the ovaries here, the majority will have arterial flow and a third actually will have venous flow.
So again, doppler is not as helpful, although it can be supportive of your diagnosis.

Quiz Cases for Ovarian Torsion

So a couple of quiz cases for you.
Here's a transabdominal scan patient with a uterus midline, you can see a mass again in the posterior aspect of the cul-de-sac in the midline.
And that should immediately alert you to the fact that this could be torsion.
So midline ovary here you can see the remaining gray scale here, but again, this large lead point of the mass, you can see it has a nodule in it.
So that makes you think, yep, this could be a teratoma.
And those are certainly prone to act as lead points for torsion.
There's doppler flow.
Does that dissuade you?
Absolutely not.
This is torsion, abnormal position, some abnormal gray scale, lead point mass trust the gray scale.

Ovarian Pedicle Sign and Whirlpool Sign

So I've been mentioning this ovarian pedicle sign as an additional sign of torsion and this is some examples from the literature.
This is again a very nice article from JUM, but you can have this sort of target appearance or this echogenic mass, but again it's circular and you can almost imagine here you can see these laminated layers basically of the tube wrapping around each other.
And here sort of more of a snail appearance similar to this mass over here.
And this is commonly encountered right at the margin of the uterus.
So you wanna try to look for this and that will give you supportive evidence that there's torsion if you can put on the color and you see the vessels actually coiling in this mass that's even more con comforting and more convincing that you are dealing with a patient with torsion.

So if you see arterial and venous flow, that's a good sign that usually indicates that the ovary is viable.
If you have flow proximally and no distal flow, that usually indicates ovarian infarction.

Ovarian Torsion on CT

So can you see this besides ultrasound?
Can you see it on ct?
And the answer is yes.
Here's a patient who had a lot of a large cyst and some a lot of gray scale abnormality here in the right ovary, you can see it here again in the midline.
But on CT you can also see this mass here with some a little bit of enhancement centrally.
And this is the twisted pedicle of this ovarian torsion.

So the whirlpool sign will add specificity and it's really useful even when you have flow present in the ovary.
In fact, it's encouraging because it tells you that the ovary is salvageable if you have arterial flow only.
Some people suggest that that means you need urgent surgical intervention.
And if there's no flow at all in that whirlpool, that means you probably are on your way to infarction.

So I've mentioned CT here briefly.
The CT findings of ovarian torsion are basically the same as you would expect from ultrasound.
It's an enlarged midline mass.
But in addition with ct we have the advantage of being able to give contrast.
So if you have a pre and post contrast image as I have here, pre contrast, post contrast hounds field units actually went down post contrast, that's partly due to just some background factors, but there's certainly no enhancement of this enlarged midline mass out of normal position.
And again, you want to look for that twisted pedicle sign.

So here's an example of where it can be helpful.
This is a 21-year-old with acute right lower quadrant pain.
She has a very large cystic mass lying posterior here to the uterus and a little bit to the right.
And her right ovary looked slightly enlarged but not particularly abnormal.
And you can see there was a normal doppler signal obtained from the right ovary.
So this was read as a large simple cyst arising from the right ovary, no torsion.
However, on CT you can see that here's a coronal view.
You can see that the ovary and the cystic mass are displaced upward and again to the midline.
And as you follow this down, you can see that here is your ovary.
This is on an axial image.
You can see here is the pedicle leading in there.
And here's uterus over here.
And then when you come down closer to the uterus away from the ovary, again you can see this twisted pedicle with enhancement.
And this actually was a broad ligament cyst that had twisted the ovary up and acted as the lead point.
So it may not be actually a mass in the ovary, it can be a mass adjacent to the ovary that acts as the torque or the lead point for the torsion.

Large Complex Masses Mimicking Other Conditions

So that brings me to my next area, which is what do we do with these large complex masses?
Well, they can be difficult because they may mimic a tumor or an abscess and that can be due to longstanding torsion with hemorrhage or necrosis.
And at these points, you need to think more about the clinical features more than the imaging.
And let me give you some examples.
Here's a patient.
She has the classic clinical features of right lower quadrant pain and vomiting, but she has this very bizarre mass.
It's actually still over on the right hand side, it's somewhat septated and it's mostly fluid looking on ct.
She has an IUD in place and here is the left sided ovary.
So this was a diagnosis of right ovarian tumor by CT and they thought it might be a cystadenoma, even an endometrioma.
And given the size of the mass torsion cannot be excluded.
This patient went actually directly to surgery and this was actually ovarian torsion and necrosis.
There was no neoplasm found.

Here's a perimenopausal woman who had two weeks of left lower quadrant pain, fever and a mass.
And you can see here is her bowel, which looks somewhat abnormal.
And they thought perhaps in an outside institution she had diverticulitis.
You can see the inflammatory changes in the fat.
You can see this very large bizarre mass sitting posterior to a uterus.
Bladder here is anterior on ultrasound.
Again, very bizarre looking mass.
Here is the bladder transabdominal.
Here's the uterus.
Here is this mass with some fluid collections.
You can see here on transvaginal, these are layering.
You almost wonder is this, are these tubes or are these pelvic abscesses with fluid debris layers that happen to be located one on top of the other.
We could find the right ovary, at least on ultrasound.
The left one it says left AA area, not sure where the ovary was.
So we were left still confused after the ultrasound.
And at this point you need to involve your clinicians and they have to make the decision.
So they actually thought it was a pelvic abscess.
And when they went to the or they did call in a gynecologic surgeon as well and an oncologist because they thought maybe it was a tumor.
But when they got to the or this was a hemorrhagic tors ovary and tube and it was necrotic and had been there for a while.

Now this 22-year-old has several weeks of discomfort.
Now she has acute right lower quadrant pain and again on ct.
This is a funny looking mass, at least with three separate collections here on ultrasound.
This one is very genic.
This is similar with maybe with clot and fluid and echoes here on the posterior one.
On transvaginal.
This one has a classic fishnet appearance.
So we were thinking perhaps this was some kind of a complex hemorrhagic cyst.
We did get good flow in what we thought was some normal ovarian tissue, but because her pain was so severe and because it was such a complex mass, she ended up going to the operating room in part to evacuate it.
And this was a large hemorrhagic cyst with no torsion.

Overlap Between Hemorrhagic Cysts and Torsion

So is there overlap?
Absolutely, there is hopefully not too much.
So hemorrhagic cyst can occasionally function as lead points and cause torsion and they can compress the normal ovaries such that you don't see any normal flow.
Again, the best discriminator is to find the gray scale version of the ovary.
Look for an abnormal position and look for that whirlpool sound sign.
And when in doubt, refer to the clinical signs and consider laparoscopy.

Conclusion

So in conclusion, for hemorrhagic cysts, when they're classic avascular with that fishnet appearance or the rightt tract clot, and if they're five centimeters or less in a premenopausal patient, these require no follow up and you can send the patient confidently on her way without adding additional testing.
If there is any question, consider a follow-up ultrasound to see if it resolves over time.
Or if there is more abnormality, some neural nodules or something that you think may be a teratoma or an endometrioma, consider getting an MR in that patient.

For ovarian torsion, it's the gray scale that you wanna count on.
Those enlarged ovaries with multiple small follicles are diagnostic midline position is highly suggestive.
And again, over 50% of torsion cases have a mass as a lead point.
So a patient with a mass and pain should raise a red flag and you should be thinking about torsion.
The difficulty arises with masses that compress ovarian flow or in patients with torsion who have persistent flow.
So that's our doppler problem and those patients look for that whirlpool sound sign and or asymmetry with the other side.

To avoid missing torsion, you may wanna keep a high index of suspicion and accept some negative laparoscopies.

So with that, I say thank you and I hope this is helpful in your practice.