The Sonographic Renal Incidentalomas (Or - Is This Much Ado About Nothing?) - HD

Introduction and Disclosures

I suspect any of my private practice colleagues,
and I was one of you for the first eight years in my career,
or for anybody who's not too snickety,
that you'll look at this talk and think, yes.
So what, because we always ignore these small things,
but we see more and more small things
as time goes on, and I hate 'em.
And I think we should ignore 'em.
And I'm gonna try and present my case why we should,
if anybody's still on the fence, I promise myself,
I wouldn't say this, but I've got to, I'm offended by this.
This means that basically the bureaucracy everywhere trust
assumes I'm gonna be immoral
and all sorts of bad things until I actually say
that I have no disclosures, I have no disclosures to make.
And I also must let you know before,
before I do this talk that I have.
This is how I operate. No opinion is worth holding
unless you can have it strongly.
So I will come across
as fairly opinionated about some of the things I'm saying.
And by the way, I never know
what I'm really gonna say in a talk
till I hear myself say it.
So I apologize if I say something stupid.

Educational Objectives

Educational objectives,
renal cancer biology is not nearly
as bad as I used to think.
And also, I think we could ignore just about all less
than up to one centimeter renal masses.
Incidentals haven't always been a problem
because you have to actually see something
before you have an incidentaloma.
And, a few years
before I started my career, this was ultrasound technology.
And I don't know how anybody read anything in this,
but, this was, pioneering when it came out.

Renal Incidentalomas

Okay. Now, as far as renal incidental lo gone,
I'm not gonna talk about tary hum
or pseudo mass from scarring or, fetal ovulation
and columns of better time.
I mean, those, those are well known.
I assume you guys all know how to, to work around those.
And otherwise, that leaves two types
of renal incidentalomas.
And I'm also not going to talk about one of the two types.
And that is you're doing an ultrasound for golf Soons,
and you see renal mass, or you're doing
a CT for something else.
You see renal mass, those are incidentalomas,
but, that's of a different category.
I'm talking about the, and they're not a such a problem for ultrasound anyway.
We don't use bosniac and ultrasound,
and I pretty much distill it too.
If there's meat, it could be cancer.
If there's no meat, it isn't.
And meat solids, thick septation, nodularities,
flow inside whatever.
So the kind of incidental lo I'm gonna be talking about are,
the little things we didn't used to see.
But now with our improving technology, we see them a lot.
And this technology can just improve.
We're probably gonna see 'em in everybody.
If you have a small, if you have discomfort
with our unequivocally saying something is such
and such, just ignore it and put in the report.
No follow up needed. You need to know that
we actually deal with uncertainty
of the renal tumors all the time
because in a large meta-analysis, 3%
of cancers were misdiagnosed as benign.
So we're already all living with this uncertainty anyway.

Now, my general philosophy towards meta-analysis is
garbage in, garbage out.
I don't like 'em. I think people who base their careers on
that just couldn't do original research.
But at any rate, this, this is on the total number
of biopsies 29 and 931.
So I trust that data.

Renal Cancer Biology

Okay, before I wrote a paper I'll describe shortly,
I didn't know nearly as much about renal cell cancer as,
as I should have, probably 'cause I'm old and lazy.
But it's actually, I was reassured
by the following statistics, one
to only one to 8% of three
to four centimeter renal cell carcinomas had metastasized
at time of discovery.
You can ratchet up a bit
and 5% metastasized by the time they're four centimeters.
So basically, a small renal tumor for all intents
and purposes hasn't metastasized.
That'll become important later.
Next about cancer, biology,
I guess in small size tumors 2.1, 3.5.
In one large study, they only grow or several studies.
They only grow at 0.13 to 0.36 centimeters a year.
So typical renal cell carcinoma is very slow growing.
In fact, they're known for hardly growing at
all over long intervals.
If you base, if you miss by what I'm talking about today,
a one centimeter renal cancer,
and if this cancer biology kind of holds through time
and through sizes,
if you miss a one centimeter renal cancer,
it's not gonna become three centimeters in size until six
to 15 years or a long time after you've missed it.
And so it's unlikely to metastasize for quite a long time
if you use a four centimeter threshold.
And if you can extrapolate those numbers, it could be up
to 20 years before, a one centimeter tumor gets
to four centimeters and has a 5% chance of metastasis.
So if you misdiagnose a tiny renal lesion
that actually someday, somewhere proves to be a cancer,
and if you call it benign,
I argued the following two points, which I cannot
quantify numerically, but I do
not think they're insignificant.
Some of those patients, maybe a lot
of 'em are gonna have some sort of other imaging study
between the six to 10 to 20 years
that their tumor grows to a reasonable size.
And if it gets bigger, it's gonna be seen then.
So, okay, so I miss a tiny one that's eight millimeters.
I don't care if somebody catches it six years later.
It's not metastasized,
patient gets therapy then I don't have an
ego for this sort of thing.
I'm going for patient care.
And so I don't care that I missed a small tumor
if that's the situation.
Also to be crude, some people are gonna die
before their cancers do anything to 'em.
So I think if you lump these two categories together,
that's a relatively high percentage of renal cancers
that you might miss that will eventually be discovered later
or not be significant.
I can't factor that in numerically or statistically,
but to me it makes a lot of sense.
Again, I strongly hold this opinion.

Small Echogenic Renal Masses

Okay, now first I broach the topic
of small epigenic renal masses.
Before I did my study, I had never retrospectively known
of a cancer that ended up being bad
or that I ever saw again, that started out
as a one centimeter or smaller genic mass.
We're seeing these more
and more often as technology improves
and we just can't follow all these up.
It's just a waste of money in my, in my opinion,
and a lot as are a lot of other things.
And oh, another gripe.
CT scans, a number
of my colleagues will describe less than one centimeter low
density indeterminate lesions.
I think that's just passing the buck
because what that means is I'm gonna
equivocate and call it this.
I'm not gonna commit myself,
but I expect a doctor who receives this report
to operate on this advice
and I hope, really hope that this doctor concludes
that this thing is benign.
I don't think that's right to pass off our obligatory duties
onto somebody who knows less radiology than we.
So as far as I'm concerned, if I'm looking at CT scan,
there's a low density renal lesion, less than one semi,
and somebody who doesn't have cancer
or a strong other history
and make me that worried, I call 'em benign.
I just blow 'em off as I suspect a lot
of my private practice colleagues do who are,
who are actually probably more pragmatic than some
of us academic types.
But I will acknowledge renal cell carcinoma can be
echogenic, absolutely unequivocally acknowledge
that I know it to be true.
That's not the point here.
I'm just pointing out that if a lesion's less than one
centimeter in its echogenic, I will show data that shows
that the chance that ever ends up being carcinoma are
so small that we can and should ignore it.
Flying in the face of
that was a prior study which said all noncalcified echogenic
sal lesions detected with ultrasound need to CT
to renal cell carcinoma.
I don't think that's true. Okay, now
to my study written up by my fellow at the time, Akatani,
who's in the audience now
and is currently at Wash U I'm very proud of her.
We did a retrospective study. We looked at adults.
These results apply to people who don't have cancer
and don't have symptoms of cancer.
So I'm not talking about somebody who's got a
melanoma or something like that.
We found 120 echogenic masses up to one centimeter in size
for which we had an MRI at C or CT to prove what they were.
Or we had stability for at least five years
and we actually had stability up to over 10 years.
And some, we had a mean stability of 7.4 years.
And also I, I didn't load my less than one centimeter
dataset with a bunch of teeny tiny things.
Most of the dataset was five to 10 millimeters.
So I didn't use tiny little things
and then bias my results up to one centimeter
of these 120 renal cell cars, echo into renal lesions.
None were cancer by our methods.
I, either used
an increase, a lack of increase in size for that actually,
okay, I'm going through the statistics of who these,
the data for who these 120 were our large largest category
was, we don't know, but it's not cancer.
66 patients
that either didn't increase in size over at least five
years or went away.
I don't know what it was. But in this sense, I don't know
what they were, but I do know what they are.
What, what I don't know is the exact name to put on them.
What I do know is they're not cancer.
And to me, that's all I'm concerned about.
A reasonable minority or angio. My lipomas.
And I'll show a couple examples of some weird things.
CAE diverticuli,
this is our typical echogenic renal mass.
Everybody sees those who see 'em a lot.
And people in my department wanna recommend CT
or MR to evaluate it now to see if there's fat,
see if it's a ML.
We also had some odd things.
This, this echogenic mass here proved
to be a casal diverticulum by anatomical matching.
This echogenic mass even proved
to be an accessory renal artery sinus
that entered the lower pole in a weird spot.
So there are a number of things these things can be,
but what they don't be is cancer.
So in summary, I would say that echogenic masses up
to one centimeter in size when you see 'em in the kidney,
not only can be ignored, but should be ignored.
I think we're wasting resources if we chase
after these, you can call 'em angio, my lipomas.
You can call 'em benign.
You can call them benign echogenic lesion
of no significance requiring no follow up
or whatever you wanna say.
But I would strongly recommend don't follow up
and don't say it's at risk for cancer.

Small Hypoechoic Masses

Okay, so we move on.
The only other basic indeterminate lesion is
what about the less than one centimeter anti coic may not
increase through transmitting mass.
Now this isn't one of 'em.
This is a seven millimeter cyst with increased
through transmission, no problem there.
But we often see this. Okay?
Now again, I suspect a reasonable number
of you guys out there, you're looking at this thinking,
why is he making a fuss about this?
I'd call that a cyst all the time.
But it isn't through transmit
by the classical definition of cyst.
You can't call this a cyst, it's gotta a through transmit.
But by analogy, I will go to a CT study this,
white paper, whatever, by Lincoln Berlin
and a who's who of experts talked about CT management
of low density lesions.
And they said, if it looks like a cyst,
but it's attenuation,
doesn't prove it called cyst basically.
So I think you can extrapolate ultrasound
if it looks like a cyst.
And allt lack access through transmission if it's dark,
doesn't look like it's got a meat in it.
I would call it cyst and never give it another thought.
Now, I routinely do that.
It small renal lesions up to a centimeter,
unless you look at it,
unless if they're echogenic, ignore 'em.
If they're not echogenic,
if you don't think you can say there's a solid component,
ignore it, called it cyst, don't even mention it.
That might be an appropriate thing in the future.
I think someday in the future, all guys just have
to not mention some of these things.
But whatever, don't recommend follow up.

Additional Notes on Renal Transplants and Vascular Findings

Okay, now I figured I would probably go quickly
and in quickly so I've got time.
Your captive audience.
I'm gonna blather about a couple of things that came up
to me as I was making this talk.
Okay? Talking about little renal cyst.
We do a lot of transplants, a lot
of places just do a lot of transplants.
Be suspicious of cyst you see in renal transplants,
but call it opera on them.
Not all cysts and renal transplants are cysts.
This said the yin y, which I'll talk about shortly,
but this waveform proves this to be a pseudo aneurysm.
So we could have called this a cyst and ignored it
and probably would've gone away.
No big deal. But we would've been wrong.
It might've been important. So I would call it doppler.
And we routinely do call it doppler all
cysts in transplant kidneys.

The Yin-Yang Sign

Now I'm gonna pull the audience.
This is an inguinal sonography, obviously yin yang.
Well, by the way, I gave a talk in China about 12 years ago,
liver transplant problems.
I had an example of a pseudo aneurysm
of the hepatic artery in transplant.
I had a translator who was, a resident in radiology
and she's translating as I spoke.
And I got to the example,
and I quite happily said, yin yang, expecting to get smiles
of acknowledgement throughout the audience.
Nothing happened. They said, what is this yin yang?
So at least in Beijing, this typically thing we think is
Chinese isn't.
And if you're speaking to somebody in a language they don't
understand and you're waiting
and waiting for a response, it doesn't happen.
You die a thousand deaths on the podium. I'll tell you.

Okay, so we got this yin yang in the groin. Alright?
Now show of hands, how many people
say this is pseudo aneurysm?
Oh, am I preaching to the choir here
or did I intimidate all of you?
Okay, it takes more than yin yang to be a pseudo aneurysm,
and I'm glad that nobody raised their hands.
I'll go through the explanation anyway.
But you don't put thrombin in this.
Now, it's possible if you put thrombin in an avf,
I suppose maybe you could thrombosis so quickly
that there are no complications,
but I don't know, I've not done that study
and there's no, I'd try to ride an IRB to do it.
So at least it seems like it'd be a
bad idea to put thrombin.
So what this actually was, was a sac a VF
with the feeding neck here from the artery,
and on the other side,
a vessel draining into the femoral vein.
Okay? So what you have to do
for any yin yang that you see in the groin,
and these aren't common, I'd say avf in our experience,
about 1% of all the yin yangs we get in the groins.
But you gotta get waveform from the neck.
And if you get a waveform with a low, low ri,
I hate the term ri, but with a low ri flows screaming
through there because it's trying to get to the side.
And you get the yin yang just
because if you've got flow going from a small pipe into a
big round area, it swirls around inside.
That's all it does. So we never call a yin
yang, pseudo aneurysm.
We demand to see a waveform from the neck.
With pan diastolic reverse flow is what we see.
So what goes in, comes back, comes back out.
And I'm one of those dinosaurs who used
to examine at the oral boards when they happened.
And I was amazed at the number of residents trying
to pass a study who didn't know this simple fact.
So this is one of my soapbox things.
If you're gonna th on both something
with thrombin in the groin,
make sure the feeding neck has p diastolic reverse flow.

Okay? Got nothing to do with kidneys,
but thank you for your attention.