Gallbladder Polyps: What To Do, When To Do It - HD

Introduction and Objectives

Hello, I'm Dr. Robert Kane.

I'm from Boston, mass, and I want to talk about a very small but interesting project that we undertook involving assessment of gallbladder polyps, how to do it, when to do it, and give you some research that we did to back up our potential plan of action.

I have no relevant financial disclosures.

The objectives of this discussion is to describe the ultrasound appearance of gallbladder polyps to discuss ways to distinguish benign from malignant polyploid lesions and to propose effective cost-efficient algorithm for following gallbladder polyps.

What size to follow and when, what to do with enlarging polyps and when to recommend surgery.

Ultrasound Appearance of Gallbladder Polyps

Gallbladder polyps are non-mobile and frequently, but not always, non-dependent Mucosal nodules, cholesterol polyps, which is one type, are usually hyper E coic to the gallbladder mucosa.

And if you interrogate them perpendicularly, you may see rever reverberation artifacts so-called ring down, or if you put cauli flow on, you may see twinkle artifact.

And once in a rare time, you may actually see a faint acoustic shadow from a cholesterol polyp.

Most of the other polyps are either inflammatory or adenomas polyps, and these are usually iso coic two mucosa and do not exhibit reverberation or acoustic shadowing.

Inflammatory polyps particularly are often small and very often multiple.

Examples of Gallbladder Polyps

Just a few examples.

This is a classic appearance of gallbladder polyp. You can see the texture is iso coic to the liver and to the gallbladder mucosa, and it is sitting on the wall in a non-dependent fashion.

Here's a group of polyps. These are inflammatory polyps that we saw in a patient who was being surveilled for hepatitis C, you can count at least five or six in this image.

Interestingly, the largest of these polyps measured up to 10 millimeters in 2004, but because they were multiple and all similar in appearance and had no concerning features, we continued to follow this patient and they have been stable for 12 years.

Here's another patient with chronic liver disease who has smaller cholesterol pulps. You can see there are more echogenic than the previous ones.

And this particular one in the anterior field is showing a ring down reverberation artifact effect, very typical for cholesterol polyps.

Interesting Case: Mistaken Gallstone

This is an interesting case. This patient had Hepatitis B and was under surveillance. We first saw the patient in 2002, and he had two gallbladder polyps identified, the largest of which was seven millimeters in measurement In 2009.

Seven years later, it was still seven millimeters in size, but in 2013, the polyp measured 10 millimeters, so it seemed to have increased three millimeters in size, which was of concern.

However, my technologist was alert to the presence of a subtle acoustic shadow and decided to investigate whether this would be mobile. So stood the patient up and indeed this so-called polyp was actually a soft gallstone, which fell to the fundus of the gallbladder and was not a polyp at all.

So no surgery was required.

The Concern with Gallbladder Polyps: Risk of Malignancy

What's the deal with gallbladder polyps? There is concern that the polyp itself could be a carcinoma or could be a precursor and develop a carcinoma later.

Gallbladder carcinoma is a very aggressive neoplasm with a five year survival of only approximately 10%, and the only effective treatment for gall bladder carcinoma is complete surgical exerter patient.

However, the vast majority of gall bladder cancers are advanced at presentation stages two to four and are not successfully resectable.

So obviously finding an early gallbladder cancer is advantageous.

Identifying Malignant Polyps

How can we tell it's a cancer?

He has a 91-year-old female who had some abdominal pain, had an ultrasound scan, and showed a large 4.5 centimeter poly point mass in the gallbladder, which showed hyper vascularity on power doppler and arterial flow signals on pulse Doppler because of its size.

She even though she was 91, we recommended surgery. This turned out, however, to be a benign adenoma, not a carcinoma. Fortunately for her, she did well after her surgery.

Here's a younger male, 48 who had right upper quadrant pain and a lesion that was 12 millimeters in 2009 when he was scanned at another institution.

When we saw him a year later, it was 17 millimeters had enlarged significantly, and therefore surgery was recommended even though this lesion was not vascular on Coli flow, because it had increased substantially in size, this turned out to be a cyst adenoma, again, not a malignancy.

He has yet another patient who was being surveilled with hepatitis C, who had a OID lesion not dissimilar to the last two with increased vascularity, and it was measuring 18 millimeters.

This turned out to be an incidental this carcinoma, and he was cured with his surgery of gallbladder carcinoma.

So the only way you can tell on a polyp, whether it's malignant or not, is to really see effects of the malignancy in terms of invasion.

So here's a large gallbladder mass that we encountered, and when you look carefully between the arrows, you can see the mass has invaded through the gallbladder wall into the adjacent liver.

And obviously a non-malignant polyp would never do that.

Here's a different patient with a large polypoid mass and careful surveillance of the liver demonstrated a focal lesion, which on biopsy turned out to be metastasis from the gallbladder carcinoma.

So in fact, benign versus malignant. You cannot judge by size or vascularity of the polyps in terms of whether they're malignant or not.

Careful. Search for invasion through the gallbladder wall for liver metastases or metastatic lymphadenopathy are really the only reliable predictors of malignancy.

And if you have a large polyp point lesion, it's probably appropriate to get either a multi-phase CT or good MR to look for evidence of metastatic disease if you don't see it with ultrasound in general.

However, if a polyp is over 10 millimeters in size, surgery is usually recommended due to the risk of carcinoma being increased.

We did show you one case with a 10 millimeter polyp as one of multiple polyps, which we elected to follow, but most of the time, 10 millimeters is the cutoff to recommend surgery.

Epidemiology and Previous Guidelines

But gall bladder carcinoma is a rare cancer. It's only one to three cases per a hundred thousand in North America, and the least common form of gall bladder cancer is the polypoid mucosal form.

On the other hand, gallbladder polyps are very common and can be seen in up to four to 7% of populations the largest being in South America. In Peru. Previous guidelines had recommended follow-up scans for all patients with gallbladder polyps less than 10 millimeters, and surgery for all over 10 millimeters.

However, this approach would seem to result in a vast number of unnecessary scans at considerable expense and possible patient anxiety.

Our Study on Gallbladder Polyps

So we undertook an organized study to see if we could define better, which polyps needed to be follow up. This was A-A-I-R-B approved study.

We identified 517 patients through a word search of radiology reports 346 of whom met our follow-up criteria.

Of that group, 43% had ultrasound follow-ups for a mean of up to 5.4 years, plus or minus 2.5 45% had no imaging follow up, but clinical follow up with a mean of up to eight years plus or minus 1.6 and 12% had surgery.

Interestingly, in this group, only 31% had actual polyps at surgery. 57% had stones but no polyps and 12% had neither stones nor polyps at the time of surgery.

This struck us as startling except, when one looks at the literature, it is well reported.

There were two surgical case series, which one of which reported 32% of ultrasound diagnosed polyps were present on pathology. And 68% had no polyps.

And then a second one reported 52% of all sun polyps were actually stones at the time of surgery.

So some things that look like polyps may be small sludge balls, soft stones, cholesterol polyps which could slough off and be passed.

And in fact, in our series, 34% of polyps resolved in the group that had follow-up imaging.

This is the distribution of polyps in our study, and you can see the vast majority of polyps are seven millimeters or less in size.

If we look at gall bladder polyp size on those who had ultrasound follow up, 34% of them resolved or disappeared, 5% decreased, 60% were stable, and only 1% showed increase in size In the groups that had a cholecystectomy, as we mentioned earlier, only 31% of them had actual polyps at the time of surgery, 57% had stones and 12% had no lesions.

If we look at the pathologic diagnosis and ultrasound sizes of the 13 polypoid lesions, we find that the cholesterol polyps and cholesterols diagnoses were all small, one of which was up to eight millimeters, but most were below six.

The and one inflammatory polyp with adenomatous change was 12 millimeters in size. The one adenoma was only seven millimeters in size, and the one hyperplastic and metaplastic polyp was 18 millimeters in size.

If we looked at all polyps that were 10 millimeters or greater, and there were only 12 in our group, you can see that most of them did not have a diagnosis of adenoma or even a lesion on some of them.

One of them had no lesion found at follow up. One inflammatory polyp had been stable at 12 millimeters and was recommended for surgery. The hyperplastic and metaplastic polyp had gone from 12 to 18 millimeters in size and surgery was recommended for that.

Results and Conclusions

So the results of our series are as follows, 81% of all polyps measured one to six millimeters, and there were no neoplastic polyps in this group.

15% were seven to nine millimeters, and in that group, one neoplastic adenoma was found. So for about 2% and 4% of the total series were in 10 to 18 millimeter size. And of that group two were neoplastic, 17%.

One was the hyper and metaplastic polyp, which had increased in size. The other was an inflammatory and adenomas polyp at 12 millimeters.

What does this mean? We conclude from this, that the vast majority of ultrasound detected polyps are non neoplastic, either inflammatory or cholesterol polyps, or in fact, even sludge balls or small stones.

Polyps below seven millimeters appear to have an exceedingly low risk for neoplasia, and in our opinion, did not require follow-up imaging. And this would take approximately 80% of patients out of the follow-up loop, saving money and patient anxiety.

In the seven to 10 millimeter group, we feel these patients should be followed initially at three or six months and then yearly if stable.

And if polyps show increase in size, that could be an indication for surgery if the measurements are reliable.

And generally polyps over 10 millimeters, we recommend surgery unless there are extenuating circumstances such as age or durability of the patient or the presence of multiple polyps as we showed earlier.

Conclusion

So with that, I conclude my talk and thank you for listening.