Ovarian Masses - SD

Evaluating Ovarian Masses: Thought Process

During this session, I'd like to describe for you the thought process that I go through when I identify a mass and I say to myself, this mass is in the patient's ovary.

This is not a talk about identifying and detecting ovarian cancer. It is a talk about a thought process that one can go through to evaluate a mass that we believe arises in the patient's ovary.

Size Measurement and the 6 cm Threshold

One of the first things and one of the simplest things that we can do is to take our electronic calipers out and simply measure the dimensions of the mass because we appreciate that approximately 70% of excised ovarian neoplasms are six centimeters in diameter or larger.

This indicates to us that once a mass has exceeded six centimeters in diameter, nearly always it has declared itself as a problem for the patient.

And if a gynecologist were to come to me and say, Dr. Philly, I excise all ovarian masses that are larger than six centimeters, they wouldn't get much of an argument from me.

That isn't to say that there aren't masses larger than six centimeters in diameter that we have followed, but in those circumstances, either the patient has refused further surgery. Second, the patient has had several laparotomies already and the mass is incredibly benign appearing, or the mass is benign appearing and the patient has had two or three myocardial infarcts. So nobody wants to operate on these patients.

This is a woman in whom we identified this, a benign appearing mass in her ovary, but it was clearly quite large. And the woman refused surgery. And in her one year follow-up, you can see that this mass has remarkably increased in size at which time she relented and had the mass surgically removed.

This also doesn't mean that we aren't going to be excising masses that are smaller than six centimeters in diameter. However, we should say to ourself that if we are recommending this excision, it should have a compelling reason for doing so.

Obviously, if a mass is discovered during surgery for other reasons, there is no downside to surgically excising it, or the mass has a highly suspicious sonographic appearance. We'll be talking about this later.

We can take some comfort in this notion of using six centimeters as our limit above which surgery is the principle likelihood for the patient.

By looking at this data from Ruland and Preston, where they looked at a group of women who are indeed the women we most worry about when we identify an ovarian mass postmenopausal women. And you can see that among masses that were less than five centimeters in diameter, there was only one malignancy out of a total of 32 lesions excised lesions between five and 10 centimeters. Of those 55 lesions, only six were malignant. And it wasn't until lesions were greater than 10 centimeters in diameter that a majority of the lesions proved to be malignant.

Okay? Just as we have set, at least for our thought process, an upper limit of six centimeters, we should set a lower limit of consideration. And that is because women who are ovulating normally typically produce a graafian follicle every month, and a mature graafian follicle achieves a diameter of 20 to 25 millimeters.

Therefore, if one identifies a unilocular thin wall cyst of 25 millimeters or less in a woman in whom we anticipate is ovulating, we can simply sign that out as a normal ovary.

So when I see ovaries that look like this with a cyst of this nature or a cyst of this nature, I don't describe this as an ovarian cyst. I describe this as a normal ovary.

Non-Neoplastic Cysts

Unfortunately for us, the literature misleads our thought processes in how to evaluate a patient's mass that we believe resides in the ovary. The literature forces us to think of the thought process as being a decision between deciding whether the mass is malignant or whether the mass is benign. This is, in my opinion, exactly the wrong notion.

When I am identifying a mass in the patient's ovary, my first thought is, if I were only smart enough, isn't it likely that this mass is simply gonna go away on its own?

That is because overwhelmingly the most likely mass that is going to occur in a woman ovary that is between two and a half and six centimeters is going to be non neoplastic.

So if the thought even goes through my mind momentarily that this mass could be non neoplastic, then I want a follow-up sonogram.

Non neoplastic cysts are the most common ovarian mass in women, no matter how you parcel it out. And they are seen in both pre and postmenopausal women. And this is especially true if we concentrate our thinking on lesions that lie between two and a half and six centimeters.

By the way, if any of you still believe that the postmen ovary is this sort of dead lump of tissue sitting in the pelvis of a woman, I hope that sonography has taught you that that is not the case. That indeed, even in postmenopausal women who are not ovulating, we frequently find cysts that appear and then subsequently disappear clearly non neoplastic.

Here's a nice example of a woman who has a right ovarian cyst with a sort of a fluid fluid level within it. And when we reexamine her ovary at a later time, we see that this is completely resolved.

What we know about non neoplastic cyst is that they will almost always spontaneously regress. By the time you've finished your career, you'll be able to count on one hand the number of non neoplastic cysts that continued to get larger and larger and you were forced to surgically excise them. And when they were excised, the pathologist said it was a non neoplastic cyst.

There are many types of non neoplastic cysts, but we're only interested in the big three, the serous inclusion cyst, not because it's a commonly palpated mass or even a commonly observed significant mass in the ovary, but because it is seen in postmenopausal women, we are interested predominantly in the follicular and corpus luteum cyst.

These are accidents relating to ovulation and in this circumstance, when women are ovulating every month, we can expect the possibility that these will show up. Quite commonly, it behooves us to go back to a time in medicine prior to a time when sonography influenced whether a surgeon was going to excise a mass from the patient's ovary.

And if we look at carpenter's large series of patients, we can see that in 80% of the instances a mass was surgically excised, which would have either resolved, almost certainly resolved on its own. And what was the payoff for all of those unnecessary surgeries?

And the answer was they found 5% of the masses that were excised were benign neoplasms. Of those 77% were benign and 23% were malignant. However, had they known that these were secondary malignancies, they would not have excised to those because there's no advantage to the patient to remove a metastasis in her ovary.

What that study teaches me is that I approach every ovarian mass in a premenopausal woman knowing that chance is strongly against it being a neoplasm of any kind, not a malignant neoplasm, but any type of neoplasm.

So if the thought occurs to me that this might possibly be a non neoplastic cyst, then by all means I wanna recommend a follow-up sonogram because if the mass disappears, I can send the patient back to our gynecologist with a report that says normal ovary. Now no one is worried about that patient's ovary, not the patient and not the gynecologist.

Unilocular Cysts

The next important question that we must ask in addition to the size is, is the lesion a unilocular cyst or not?

The reason that we are interested in whether the cyst is unilocular is because non-plastic cysts are unilocular. So if we're in the right size range and the mass is unilocular, then even more so we are convinced that it may be a non neoplastic cyst.

These structures here, by the way, are not daughter cysts and these are not septi. These are developing small follicles in the remaining ovarian tissue, which help us to realize that indeed this is an ovarian cystic mass.

Now we're all aware that many benign ovarian neoplasms are also unilocular cysts. And here we see two such examples. This one is echo free. This one has low amplitude echoes. And by the way, even if the lesion has some tiny mural nodules, I still consider it to be a unilocular cyst.

So what we do know is that if the unilocular cystic mass turns out to be a neoplasm, then almost always it turns out to be a benign neoplasm.

In these 212 unilocular cystic ovarian neoplasms that were surgically excised only three turned out to be malignant neoplasms, which mean, and those of those three two were greater than 10 centimeters in size.

So what we can say is that if we follow up a unilocular cyst and the unilocular cyst turns out to actually be a neoplasm so it doesn't disappear, then 98.5% of the time we can be confident that that neoplasm is actually benign.

What is also true about Unilocular cyst is that there are a large number of them, and if it is your plan to try to decide exactly which unilocular cyst you're looking at, then you can plan for a lot of disappointment in your life.

The very common ones are the follicular cyst, the corpus luteum cyst, and the endometrioma. Less common is a para ovarian cyst, the serous inclusion cyst or the serous cyst adenoma. This is the first neoplasm we have encountered in our list.

Also uncommonly, we will see cystic teratoma mucin cyst adenoma or cyst adeno fibroma. These are not uncommon neoplasms, but they are uncommonly identified as unilocular cysts. And rarely we will see a cystadenoma of low malignant potential and very rarely a serous cyst adenocarcinoma.

Now, I have never personally seen a serous cyst adenocarcinoma as a unilocular cyst, but they do occur and but only very rarely I have seen some cystadenomas of low malignant potential three to be exact. And I will share two of them with you during the course of this lecture.

This is the first one here is the mass. It is a unilocular cyst. It has a lot of low amplitude echoes in it. It did have some tiny mural nodules, but as I've already told you, I do not consider that as evidence that it isn't a unilocular cyst.

This was a woman in her mid fifties. This is her CT scan, which again shows areas of wall thickening in the mass. So what you can say is that a mass of this size and a woman of her age is going to be surgically excised. Of course, the anticipation is that we will excise a benign ovarian neoplasm.

So we're all a little surprised when the pathologist comes back and tells us it's a borderline carcinoma.

Now to be perfectly honest, I have long since given up trying to decide what a pathologist is gonna call a borderline carcinoma. This is something that would make sense to me.

Here's a lesion that is unilocular, but it has a thickened irregular wall in this area. And if a pathologist signed that out as a borderline cancer, at least that would make sense to me.

But this thing has a markedly thickened irregular wall, and I would've thought that this was a frank cancer. But the pathologist again signs this out as a borderline cancer.

So that unilocular cyst, the cyst with the irregular thickened wall and the cyst with the very irregular and thick wall, all were read out by the pathologist as borderline cancers.

Endometriomas

We are particularly interested in the endometrioma because it is a unilocular cyst which will still be there when we bring the patient back for a follow-up sonogram.

Endometriomas can in fact occur anywhere from the diaphragm down into the inguinal canal, but most often they occur within the ovary. About 80% of endometriomas occur within the ovary.

As you know, this is a pathological lesion that is characterized in its gross pathologic state with a fibrotic wall containing either new or old blood in the lumen. Most often old blood.

These are most commonly unilocular and when they are, they are often typical in appearance, but occasionally they are multilocular and when they are, they can create some confusion.

Here we see an endometrioma with fairly typical findings. Again, the wall is usually visible. The wall helps us to know that this is a cystic mass and the mass is characterized by low amplitude echoes.

Occasionally we will see a fluid fluid level in these lesions, but typically we do not. Here we see a lesion that has, again, low amplitude, echoes, visible wall and acoustic enhancement.

If in addition to that we see these tiny little bright reflectors in the wall, we can be virtually certain that it is an endometrioma.

As I said, endometriomas are occasionally multiloculated, and when they are, we may start thinking we're looking at a neoplasm of the ovary. In this regard, MRI is very, very helpful to us because MRI is virtually diagnostic of an endometrioma.

If we see high intensity signal in the lesion on T one weighted spin echo images and high intensity on T one weighted spin echo images with fat saturation. If we see that, that virtually excludes all other diagnoses.

Here we see a patient with two lesions. The lesion on the left, we diagnosed pretty confidently as an endometrioma on our sonogram, the lesion on the right because of this irregularity we didn't feel so confident about. So an MRI was done, but we can see that on the T one weighted spin echo images, they are both bright and on the T one weighted spin echo images with fat saturation, they remain bright.

This one may look funny, but it is an endometrioma.

As I said, this is a lesion which will typically and invariably persist when we do a follow-up sonogram on the patient.

In the instances where I suspect that an endometrioma is a neoplasm, I do feel somewhat bad if the patient goes to surgery, not because they had a surgery, because generally speaking, in large endometriomas are going to be surgically excised anyway. But I do feel bad that if I suspected that it was a neoplasm because then the patient goes to the operating room worried that her neoplasm may be malignant and her anxiety is not quelled until a histopathologist tells her that the lesion is a benign lesion.

So to avoid that circumstance, I recommend an MRI in any lesion that I think is a neoplasm. But within that lesion I see low amplitude echoes, which is one of the hallmarks of endometrioma. 95% of endometriomas demonstrate low level echoes.

Suspicious Features Indicating Neoplasm

Obviously, if we see features which strongly suggest an ovarian neoplasm, then we're not gonna be thinking about asking for a follow-up sonogram. And what kind of features are these?

Well, I'm sure you know this list as well as I do, and certainly at the top of the list is septations. You can't spend but two or three minutes thumbing through a textbook of gynecologic pathology without realizing that ovarian neoplasms are characterized in many, many instances by the presence of septations.

Here we see a large mass clearly larger than six centimeters, and it has within it two thin septa. And we can say that we still believe this to be a benign neoplasm.

On the other hand, here we see a large cystic mass in the ovary characterized by thick and irregular septa. In this instance, we are very concerned that the patient may have an ovarian cancer mural and septal nodules, mural nodules, very characteristic of ovarian neoplasia.

Not definite evidence that it is a malignancy by any means, but septal nodules virtually always mean that the patient has an ovarian cancer. So a very disquieting feature for ovarian cancer.

Here we see another patient with a large cystic ovarian mass. It has many true septi and a large septal nodule. Again, our concern would be very high that this is ovarian cancer.

If we see a thick or irregular wall, I've already showed you an example of that, but here's an example on a CT scan of a large multilocular ovarian mass, and about a 50-year-old woman, which also has a thick and irregular wall, obviously, this is something that should be surgically excised.

Here we have a remarkably thick and irregular wall irregularities of septi and septal nodules. These are the kinds of things that make you highly suspicious of ovarian neoplasm and particularly ovarian cancer.

Seeing flow in septi also is something that causes you concern bright echoes or shadowing echo densities.

Now here we see an ovarian mass wherein we identify numerous bright reflectors as lines and dots. The wall is thick, but more importantly, we identify an area of regional bright echoes that casts an acoustic shadow.

Now this is unambiguous evidence that we're looking at a neoplasm, but not a malignant neoplasm, a benign neoplasm, a cystic teratoma.

Here we have a patient that has this very large, scary looking mass in her pelvis, but when we analyze the findings, we develop a great deal of comfort because here is an area of regional bright echoes that casts an acoustic shadow.

Here is an area of regional bright echoes that casts an acoustic shadow. These areas of bright echoes that don't cast an acoustic shadow are not as helpful to us, but when we see those areas of regional bright echoes casting and acoustic shadow, we can diagnose this as a large cystic teratoma benign, but still undoubtedly will be surgically excised.

Here we have an example of an ovary with a mass within it that is so small it doesn't even deform the ovary. Again, we have an area of regional bright echoes. It doesn't cast an acoustic shadow, so that doesn't help us as much.

But here we have an area of regional bright echoes that does cast an acoustic shadow that is a dermoid.

The reason that I'm so confident is the three most common things that produce these findings are all pathognomonic for dermoid. They are fat filled Rokitansky protuberance in the wall, a hairball or tooth and bone.

Indeed, in a study we did where we looked at 252 patients with ovarian masses, commonly cystic teratoma was the diagnosis. And if we look at these as a hundred percent of the cystic teratomas, we can see that sonographically we were able to, we said that 64 of these were indeed cystic teratomas, and only once were we incorrect.

And when we were incorrect, it did not turn out to be an ovarian cancer. It turned out to be an endometrioma, another benign lesion.

Solid Masses and Hemorrhagic Cysts

And then finally, if the ovarian mass is solid, we are very concerned about the lesion. Here we have a sort of a tri lobe solid ovarian mass. Here we have a sort of a single solitary ovarian solid mass. Both of these are indeed a malignancy.

My rule for solid ovarian masses is that they all belong in the pan. However, it is not true that all solid masses are malignant. There are benign, solid tumors of the ovary, the Brenner tumor and the fibroma coma group of ovarian neoplasms.

What is more difficult to know is which of these two lesions is a primary lesion versus which one is a metastatic lesion to the ovary. This turned out to be a metastatic lesion.

So whenever I see a solid ovarian neoplasm in the ovary, my, one of the things I first think of is does this woman have the type of primary cancer elsewhere that might metastasize to the ovary, leukemia, lymphoma, breast cancer, gastrointestinal cancer?

Well, one of the common lesions that presents as a solid ovarian mass in a woman with other intercurrent malignancy is a lymphoma. So here we see actually some solid masses within the ovary in a woman with lymphoma.

Now, one of the problems that we run into is that hemorrhage into the cyst is a common phenomenon, and occasionally the hemorrhage that occurs into the cyst can present us with a confusing sonographic appearance.

So diffuse echoes may make us think we are looking at a solid lesion. Adherent clot may make us believe we're looking at a mural nodule and fibrin strands may make us believe we're looking at septations.

However, let's for a moment imagine that we were all smart enough to realize that it was indeed a hemorrhagic cyst. Well, what a phenomenally useful conclusion that would be because hemorrhagic cysts are most commonly follicular or corpus luteum cysts, which means not only are they benign, but they're gonna go away by themselves.

It is true that there is an occasional benign ovarian cystic neoplasm that gets hemorrhage into it. But these have, thus far in the literature all turned out to be benign. When you see hemorrhage described as indicating malignancy, that is hemorrhage into the solid component of an ovarian mass.

So if we were to know that the lesion was hemorrhagic, not only would we be almost certain that the lesion is benign, but we would almost be certain that it would resolve on its own.

As I said, diffuse echoes may make us believe that the lesion is solid. Here we have a lesion that is characterized by diffuse low level echoes. It's not very convincing acoustic enhancement. It would be very difficult to know whether this was some solid ovarian mass versus an endometrioma adherent clot may make us believe.

We're looking at a mural nodule here. We see this ovarian mass with this feature that looks like solid material. Indeed, however, we can recognize this as a blood clot because it has convex margins and no mass grows with concave margins as seen in this retracting blood clot.

All neoplasms grow with convex margins. Another feature that is helpful is that if this were a malignancy growing in from the wall, it would tend to have the same echogenicity of the wall, which obviously this blood clot does not.

Here we see that true mural nodules have convex margins and they have the same echogenicity as they grow in from the wall.

Fibrin strands can be particularly vexing because they may make us believe that we are looking at septations in the ovarian mass. So here is a lesion that looks like it may be septated, and if that is what we believe and we do not ask for a follow-up sonogram, we will end up with a problem on our hand because when this patient is finally taken to surgery, almost certainly this mass will have completely resolved.

Discriminating clot and fibrin strands within the clot as being different from septations can occasionally present a challenge, but usually it is fairly straightforward.

One of the characteristics of fibrin strands is that there are simply too many of them to be septations. Now I've certainly seen large ovarian cystic neoplasms with 20 or 30 septations in them, but you don't see 20 or 30 septations per cut.

And here you can appreciate that these fibrin strands don't make a lot of sense. They don't flow nicely from one to the other. As you would see with septations here, here in a septation, the septi flow one to the next one, to the next here in this hemorrhagic cyst, the septi don't make any sense to you.

Another aspect of clot retraction is that it may produce a flat surface as the blood congeals in a clot fluid level. Again, there are no solid neoplasms of the ovarian wall that grow with flat surfaces, so these cannot be growth of neoplasm.

Here we have a lesion that admittedly looks a little funny and could this be a solid component or some neoplastic component in this mass, or are we looking at a retracting clot?

When I, whenever this question arises in my mind, even for the slightest briefest moment, what I want is a follow-up sonogram. And it's a negotiation as to how long you wanna wait for that sonogram because here's a sonogram performed only 10 days later, and you can see that a blood clot is always gonna change remarkably during any short interval of time.

Solid tissue is not going to change, whereas a blood clot will change dramatically. If you can't wait 10 days, can you wait three days? And even in three days, a retracting blood clot will retract observably more than it has been.

The reason that I wait six weeks to recommend follow-up sonograms is because at six weeks, the ovary will almost invariably appear entirely normal. So now I can send the patient back to her doctor with a report that says normal ovary.

Although hemorrhagic cysts may be confusing, in fact, we very commonly are accurate when we diagnose a hemorrhagic cyst. In that group of 252 patients, there were 28 that we evaluated with hemorrhagic cysts and 27 times out of 28 when we called it a hemorrhagic cyst, we were correct in the other instance, it wasn't ovarian cancer, it was again an endometrioma, which typically don't have fresh blood within them when we examine them, but occasionally they do.

There were no neoplasms in this group.

Role of Doppler in Assessment

Now we have either identified a mass which is persistent. We have considered our alternative imaging techniques, or we have seen features which strongly suggest an ovarian neoplasm. Is it now time to ask the question, is it benign or is it malignant?

And we are getting closer, but we're not there yet because as you know, there are two schools of thought in the evaluation of whether a lesion is benign or malignant. There is the School of Morphologic assessment, which is essentially what we have been talking about for the past 30 minutes or so.

And then there is the School of Doppler assessment, which says that malignant lesions all have abnormal arterials within them because the muscular wall of this arterial is abnormally formed. That results in an inability for that arterial to contract well and create high resistance to flow.

That means that these lesions will tend to have low resistance to arterial flow. And of course, sonography has several tools available by which we can very easily measure resistance to arterial flow.

So is doppler the answer to deciding whether or not the lesion is benign or malignant? And the answer is no more so than was morphology. This is for many reasons, but the most important of these is that doppler cannot be thought of as being independent of morphology.

Is there anyone in our, my listening audience who actually asks their sonographers to simply do a resistive index of any mass they find in the ovary? Don't take any pictures of it. Just write the resistive index on a piece of paper and put it on their desk for later interpretation.

Of course not morphology is always obtained first. The question isn't, can doppler separate benign from malignant lesions? The real question is, does Doppler add anything to the morphologic impression that we have already formed?

In order to understand that, we have to understand how sonography as a morphologic evaluator does in discriminating benign from malignant lesions. And if we look at this study from Granberg, we could look at many one of dozens of studies.

What we begin to realize is that when sonography predicts that a lesion is benign, we do much better than when we predict that the lesion is malignant. So a sonographic diagnosis of malignancy has a very high probability of being right.

So when we see this unilocular cystic neoplasm of this patient's ovary, I ask you, would a doppler change your mind? The answer should be no. We would not then go on to call this lesion malignant because we got a low resistive index from the wall of this lesion.

In order to understand how ultrasound does well in the diagnosis of malignancy, it's worthwhile to look at the data of Cummings who actually looked at 861 ovarian neoplasms. Remember, carpenter's data were a large number of excised ovarian masses from the ovary, most of which were not neoplasms.

In this instance, we're looking at a large number of neoplasms that have been excised from the ovary. And it's somewhat surprising to realize that the vast majority of ovarian neoplasms are actually excised from the ovary of premenopausal women.

So why are we so worried about postmenopausal women? And the answer is that of the 25% of ovarian neoplasms excised from postmenopausal women, more than half of them are malignant. And that is our level of concern of these lesions, 75% were benign, 21% were malignant, and 4% were recorded as low malignancy potential.

Now understanding that in carpenter's era they didn't have a designation of low malignancy potential, you could take about half of these and put 'em here and half and put them there and you get exactly the same numbers. That carpenter had 77% benign, 23% malignant.

If you look at a textbook of gynecologic pathology, you realize that there are a very large number of histologic types of benign ovarian neoplasms. But what the textbooks don't show you very well is that a minority of these histologic types actually comprise the vast majority of clinical masses acids.

If we look at Cumming's data of benign ovarian neoplasms, that is 645 benign ovarian neoplasms, an absolutely whopping number, we can see that almost 60% of the time the lesion turned out to be a cystic teratoma. 37% of the time the lesion turned out to be a cystadenoma, which means that 95% of the time the lesion was either a benign cystic teratoma or a benign cystadenoma.

So if you ever wondered why it is you feel comfortable with the look of a cystic teratoma or a cystadenoma, it is because these are the ovarian neoplasms you get an opportunity to see. Occasionally there's a benign stromal tumor or a Brenner tumor.

How about malignant ovarian neoplasms in their series? Well, obviously serous cyst adenocarcinoma was the one most commonly seen. But then we have undifferentiated carcinoma, endometrioid carcinoma, mucinous adenocarcinoma, germ cell carcinomas, sex cord carcinomas.

What do those look like? And don't they have a variety of appearances? And the answer to that question is of course, yes, but that's not the question to ask.

The real question that we want to ask is, how likely is it that any one of those malignancies is going to look like one or the other of these three benign lesions? And the answer to that question is not very often, which means that when we diagnose a lesion as a benign serous cystadenoma or a benign cystic teratoma, we are going to be right almost every time.

The biggest problem that we encounter is not calling malignant lesions benign, but benign lesions malignant and mucinous cystadenomas are usually very complicated looking ovarian lesions, which immediately make us think we may be looking at a serous cystadenocarcinoma or a mucinous cystadenocarcinoma.

So it is this that gives us a greatest degree of problem.

As we said, benign lesions tend to demonstrate high resistance to arterial flow. And malignant lesions tend to demonstrate low resistance to arterial flow. The line of division between high and low resistance is usually a resistive index somewhere around 0.4.

Now here we see a lesion in the ovary. We measure the resistive index. It's 74. That would tend to indicate to us that it's benign, but hopefully when you look at it morphologically, you would say this is a hemorrhagic cyst. So not only is it benign, but it almost certainly will go away by itself.

Here we see morphologically a mass with daughter cysts and septal nodules. And typically we would be suspicious that this is an ovarian cancer by morphology. We do a resistive index and indeed we get a resistive index of 25 well below our cutoff of 0.4.

However, here we see a solid mass in the ovary. Again, we appreciate it's an ovary because we can see these small immature follicles. And when we take a resistive index, we took a variety of them and generally they were around 59.

So would we now call the solid lesion benign because we got a low resistive index in it? And I hope the answer to that question in your mind is no. All solid masses are considered malignant until they are proven benign.

And by the way, this is the smallest ovarian cancer I have ever personally diagnosed. So I have never seen one of these ovaries, although I'm sure they exist wherein there is no visible mass in the ovary. But the ovary is excised and cancer is found within the ovary.

My experience is that one always detects an ovarian mass when ovarian cancer is present.

Now here we have a lesion that is much greater than 10 centimeters in diameter, but it is a unilocular cyst. So even though it's larger than 10 centimeters in diameter, I'm thinking that morphologically this lesion is benign. We do take resistive index and resistive indices are in the benign range.

So both by morphology and resistive index, we think that the lesion is benign. But this is the second of the three borderline cystadenocarcinomas that I have seen that turned out to be unilocular cysts.

What can be said of doppler sonography of ovarian masses is that if you measure the resistive index of a large number of benign lesions and a large number of malignant lesions, and you look at the mean resistance, there will be a higher mean resistance in the group with benign lesions than in the group with malignant lesions. And the distance between them is often statistically significant.

Unfortunately, that piece of information does not mean that this is a useful method of separating benign from malignant lesions. One of the main reasons for that is exemplified by this case.

This is a 65-year-old woman with this larger, very nasty looking ovarian mass with very thick septing and a very large mural nodule. Now unambiguously, we would call this an ovarian malignancy. And in fact, from a morphologic perspective, we would say that the luckiest day in this woman's life would be if this lesion actually turned out to be benign.

But we started to take resistive indices in it, and there we took one and it was an extremely high one. We took others, they were all very high, and we kept looking around until we found this little daughter cyst where indeed there was a low resistive index.

Indeed, when we looked at our data, we could see that in virtually every mass where you measured multiple resistive indices, you could find a difference in resistive indices anywhere within the mass. And that was true of benign lesions as well as malignant lesions.

I presented this data at a conference where Dr. Kurjak, who started all of this issue with resistive index measurement in ovarian neoplasms was present. And when I finished presenting this data, Dr. Kurjak stood up and said, Dr. Philly, I agree that there is variation in the resistive indices among masses, but you must continue searching until you find the lowest resistive index and that is the resistive index, which you must pay attention to.

Well, I answered and said to Dr. Kurjak, Dr. Kurjak, you are making my point. If you identify a unilocular cyst and you take a resistive index and it's 70 and you take another and it's 75, how persistent are you then looking for an even lower resistive index?

And the answer is, you are not because you believe the lesion to be benign, but if you see a lesion that you believe to be malignant, you very commonly keep searching that lesion until you find a resistive index that helps to cement your morphologic diagnosis of malignancy.

So the very nature of the process tends to lead you to look for low resistance in lesions you believe to be malignant morphologically, and not to continue looking in lesions that you expect to be benign.

Now, having said that, you may feel that I don't think doppler sonography is valuable in the evaluation of patients with ovarian masses, but nothing could be farther from the truth. In fact, I don't believe that we should ever evaluate an ovarian mass without using doppler sonography, but it isn't spectral doppler sonography that I'm interested in.

I'm interested in color doppler sonography, particularly sensitive color doppler sonography.

Here is a mass in the ovary, which is obviously a very unusual and scary looking mass, but here we see some things that could be fibrin strands sticking off of a blood clot. So if I could convince myself that this material might be blood clot, then I might be more interested in a follow up examination of this patient.

However, when we turn on color doppler and we see that there is a blood vessel running through the middle of this material, so this is solid ovarian neoplastic tissue and the thought that it could be a blood clot is no longer in my mind.

Here was a lesion that I was almost ready to call an endometrioma looking at the scans when all of a sudden I looked at the next scan that came up and it was a doppler sonogram showing that there was an artery running right through the middle of this mass. Now that tells me that this is not an endometrioma, it is a solid neoplasm of the ovary and I don't really care what the resistive index is.

That is a lesion that should be surgically excised.

Now here's a lesion in the ovary. Is that an endometrioma or a solid mass? And we turn on color and the answer is that mass has flow in it, and that is a solid mass.

Also, no hemorrhagic cyst is a hemorrhagic cyst until it is proven to be color doppler negative. So here we have a patient where we identify this very small mass in her ovary with some low amplitude echogenicity in it. It doesn't really acoustically enhance, is that mass a solid mass or not?

I'm going to look at it with color doppler sonography. And when I look at it with color doppler sonography, I find a blue dot and a red dot. Now is that an artifact or do those actually represent blood vessels in this mass?

And the way to answer that is with spectral doppler sonography. And when we do a spectral doppler sonogram, we identify that that red is indeed an artery and therefore we now know this to be a solid mass. And even though it's small, we want that mass surgically excised.

Conclusion

I hope I've given you some guidelines which will help you the next time you encounter a patient who has a mass in their ovary. And I'm reminded at this point in the lecture something that one of my mentors taught me.

What he said is Dr. Philly Roy. Of course, I can't guarantee that I am right, only that I have been reasonable. And what I have tried to give you today is some reasonable things to do.

And in order to at first stay the surgeon's hand in excising ovarian lesions unnecessarily, and then on the other side make a reasonable estimate of what is likely to be benign and what is likely to be malignant.

Thank you very much.