Hepatobiliary: Unusual but Instructive Cases - HD

Unusual but Instructive Hepatobiliary Cases

My name is Aya Kamaya and I am from Stanford University.

I am gonna talk about unusual but instructive hepatobiliary cases.

In this talk, I am gonna show you some unusual but instructive cases that have relatively common presentations: cases that have echogenic portal triads on ultrasound, cases that have echogenic material in the gallbladder, and then finally, cases with biliary ductal dilatation.

Echogenic Portal Triads

This is the first case. This is a 43-year-old female who has diabetes and end stage renal disease. She came in for an abdominal ultrasound. The thing that is really unusual about her liver is that her portal triads are very echogenic. If you look at them, they are just kind of diffusely throughout the portal triads. There is a still image of the liver and you can see that the echogenicity actually have a parallel kind of tram track configuration. In some areas there is this reverberation artifact.

What could be giving this imaging appearance? The differential diagnosis for echogenic portal triads includes biliary gas. Maybe it could be hepatolithiasis, hepatic artery calcifications is another possibility. Portal venous gas is a thought. Cytosis can give very echogenic portal triads.

In this case, we see that there are these very echogenic linear echoes that are in a parallel configuration. The reason why we see that is because we are actually seeing both sides of the arterial wall within the liver. In areas where the arteries are oriented perpendicular to the transducer, they act as a specular reflector. Because there are two sides, you get a reverberation artifact. In some areas we see a little bit of posterior acoustic shadowing, although I would not say that that is the predominant sonographic finding.

If you see that same appearance in the splenic hilum, as in this image in the same patient, I do not think anyone would have any difficulty in making the diagnosis of arterial calcifications. That is what this is. This is hepatic artery calcifications and this is the same patient's non-contrast CT. We see that the hepatic artery is just densely calcified. In addition, the other smaller arteries are also quite densely calcified. The splenic artery here, including its branches are densely calcified.

We do not often think about hepatic artery calcifications because it is actually sort of an unusual condition. Most people, there is some sort of mechanism that allows the hepatic artery to avoid calcification and thrombosis in most people, except in patients who have renal failure and are on dialysis. Those patients, they often go on to have a secondary hyperparathyroidism and then that leads to generalized calcifications throughout the body, including the hepatic artery.

Here is a different patient with really densely calcified hepatic arteries throughout the liver and confirmed on this non-contrast CT scan. It is thought that the longer patients are on dialysis, the more likely they are to have calcifications.

Here is a different patient also with very echogenic portal triads. In this patient they have a history of a recent ERCP. If you look at those echogenicities, they are actually interrupted and they are moving with the patient's positioning. This patient is breathing and you can see that some of these little foci are just ever so slightly moving. In this case, not only do we see echogenic foci that are moving, but sometimes you will see a little bit of dirty shadow or what we call ring down artifact. Usually these patients have a history of prior instrumentation, sphincterotomy, stent placement, surgery, such as a choledochoduodenostomy. If they do not have any history like that, then you wanna start thinking about some sort of spontaneous cause such as a choledochoduodenal fistula.

This is an example of biliary gas and this is probably the most common cause of echogenic portal triads. The same patient, different orientation where we see these echogenicities and a little bit of this dirty shadowing. This is the same patient's CT where we see the gas within the biliary tree. That was caused by a stent that is allowing retrograde flow of gas from the bowel into the biliary system.

This is a different patient who has an unusual appearance of their portal triads. We are looking at the portal vein here. The thing that is really pronounced is that there are multiple echogenic foci within the portal vein. When you see that, you wanna think about two possible etiologies. This could either be gas, so maybe this is portal venous gas, or possibly it could be rouleaux formation where you get little the red blood cells can sort of coalesce and you can see some of those red blood cells.

To help differentiate between the two, what you want to do is put spectral tracings on the portal triads, which we see down here and with portal venous gas. What you are gonna see are these little blips in the spectral tracing. Those are high intensity transient signals or HITS. When you listen to the ultrasound machine, you will have this pinging sound on spectral Doppler. That confirms that that is indeed portal venous gas.

When you have portal venous gas, the next thing you wanna think about is what is causing that portal venous gas. The thing that most commonly causes portal venous gas is pneumatosis of bowel. That in turn can either be caused by bowel ischemia, which can be quite morbid and even fatal or benign pneumatosis. In this patient who was 70 and had severe abdominal pain, we recommended getting a CT scan for further evaluation. He indeed had multiple dilated loops of small bowel with pneumatosis, a lot of free fluid. In addition on the CT we can see that there is this tiny bubble of gas in the superior mesenteric vein and this tiny bubble of gas in the right portal vein. We can actually see the portal venous gas better on the ultrasound compared to the CT. In any case, he had pneumatosis caused by bowel ischemia and he actually passed away two days after the CT scan was obtained from that bowel ischemia.

Different case, a different patient with very echogenic portal triads. In this case it is so echogenic that it is causing shadowing really pronounced posterior acoustic shadowing. This material that is very echogenic is distending the biliary tree and in some areas we see twinkling artifact associated with that. In this case, the echogenic portal triads are caused by hepatoliths or hepatolithiasis. A very common cause of intrahepatic hepatolithiasis is recurrent pyogenic cholangitis, which is a condition where you have bacterial superinfection of the biliary system leading to bacterial cholangitis that then causes or allows intrahepatic calcium bilirubin stones to form. That leads to obstruction. These patients have repeated bouts of cholangitis and stone formation. Usually they have a history of malnutrition superimposed upon a coliform bacterial infection. With these patients, because they get repeated bouts of stone formation and cholangitis, they do need to be treated by evacuation of the stones within the biliary system. This patient did have an ERCP to get their stones removed.

This is a different example, a different patient with very echogenic portal triads. You can see on the cine and the still picture, but the liver, not only are there very echogenic portal triads, but there is some morphologic changes within the liver. This is a cartoon that kind of depicts what the changes look like. In this case we see very hyperechoic and thickened walls of the portal venules and some people call this the clay pipe stem appearance or tortoise shell appearance. This type of appearance is caused by Schistosoma mansoni infection, which is a trematode blood fluke infection kind of endemic in South America, the Caribbean, Africa, and the Middle East. The reason why they look like this is that there are these eggs that get deposited into the veins, which then creates or causes a granulomatous reaction. That leads to irreversible fibrosis and portal hypertension within the liver. This is a patient with schistosomiasis caused by Schistosoma mansoni.

There are other types of schistosomiasis, other types of schistosome infection. There is another type called Schistosoma japonicum, which causes a slightly different appearance to the liver. You get more of a calcification that occurs within the liver and that separates the liver into these echogenic septa. That is called a fish scale appearance. Sometimes you will have calcifications within the bowel as well. Schistosomiasis affects both bowel as well as the liver. In this patient, he was a Filipino male who presented with melanoma. He ended up getting a colonoscopy and biopsy of his colon and that showed that there were eggs from Schistosoma japonicum in his lamina propria.

Those were cases that I found to be somewhat unusual and challenging that presented with echogenic portal triads, although the majority of cases that we see are probably biliary gas, you do wanna think about these other possible entities including hepatic artery calcifications, portal venous gas, hepatolithiasis, and schistosomiasis.

Echogenic Material in the Gallbladder

Next case, this is a 70-year-old female who presented with right upper quadrant pain. When we have patients who have right upper quadrant pain, we typically like to look at their gallbladder. In this patient's gallbladder we see that it is quite distended. Within the gallbladder we see this echogenic material in the gallbladder, on color Doppler, there is no detectable flow within the echogenic material. The wall of the gallbladder is relatively thin, there is no pericholecystic fluid, there is no hyperemia of the gallbladder wall.

What could be giving this patient this sonographic appearance of echogenic material in the gallbladder? The differential diagnosis for this could include sludge. Maybe it is just really echogenic sludge, like tumefactive sludge. It could be blood. That could be hemobilia or hemorrhagic cholecystitis, potentially maybe it is pus. We did not see any stones in this patient. When you think about infection, you think about cholecystitis since there are no stones, you think about acalculous cholecystitis. Alternatively it could be gallbladder cancer, although we did not see any detectable flow within it. You also wanna think about gallbladder wall thickening occasionally really marked gallbladder wall thickening can look quite unusual.

This patient also had an unusual finding in the left lobe of the liver. In the left lobe of the liver, there is this rounded structure on color Doppler, we see that it fills partially with both red and blue. That is a very characteristic yin yang appearance on color Doppler and with spectral tracings right at the entrance of where you see that flow, we see that there is both inflow. This is a characteristic imaging appearance of a pseudoaneurysm in the left lobe of liver.

This patient also has a history of multiple vascular dissections and she actually presented with melena. Those are very pertinent histories that can help you make this diagnosis. In this patient, she had a bleeding hepatic artery pseudoaneurysm that led to hemobilia. This is the same patient CT where we see that pseudoaneurysm in the left lobe of the liver on axial views. Same thing on coronal views, we see the blood that is in the pseudoaneurysm. Actually she came in from an outside hospital and they thought that was a hemangioma. I would say that the ultrasound is better able to characterize that lesion as a pseudoaneurysm than the CT. In any case, there is also blood in the gallbladder as well.

This patient has hemobilia, and with hemobilia this occurs because of a fistula between a vessel and the biliary system. These patients present with what is called Quincke triad, where patients have upper abdominal pain, an upper GI bleed and jaundice. Usually there is some sort of history that can help, such as prior instrumentation or trauma. In this case, they had a history of vasculitis. Sometimes vascular malformations can lead to hemobilia and then rarely ascariasis where you get those worms that kind of burrow through the liver. That can cause a communication between a vessel and a biliary system.

Different patient also with right upper quadrant pain and melena, again, we were not given the history of melena, but anyway, this man had distended gallbladder echogenic material in the gallbladder, avascular acellular. This was thought to be sludge, but in this patient he too had a bleeding pseudoaneurysm in the left lobe of the liver, which we can see on this volume rendered image. The hepatic artery is quite dilated and in fact there is a little dissection there. This bleeding pseudoaneurysm in the left lobe of the liver.

This is a different patient who had a recent liver biopsy and he too had lots of echogenic material in his gallbladder from that liver biopsy causing hemobilia.

Sludge is usually the reason why we see echogenic material in the gallbladder. We see sludge all the time. This is caused by precipitation from bile of cholesterol crystals, calcium bilirubin pigment, or other calcium salts. When we see sludge, there is almost always a reason, or at least there should be a reason you do not see sludge in normal well patients. Usually you see sludge in people who have had prolonged fasting, often in ICU patients, patients who are on TPN, patients who are pregnant or have recently experienced some rapid weight loss or biliary obstruction. Usually with sludge it is just this fine these fine echoes that sort of layer out within the gallbladder. Occasionally sludge can become sort of crystallized as we see in this patient who has just echogenic material in the gallbladder that has really pronounced twinkling artifact on color Doppler.

I just wanna make a quick note about twinkling artifact. It is actually twinkling artifact, not twinkle artifact. Please use the word correctly. It is twinkling artifact.

Sludge sometimes you can look more solid in appearance and when it is more solid looking we call that tumefactive sludge.

This is a different patient also with echogenic material in the gallbladder, in her gallbladder. In this patient she has a history of sepsis. She came, she has sepsis and hypotension. If you look at the gallbladder, it is a little, there are some secondary findings that can help in making this diagnosis. First of all, not only is there echogenic material within the gallbladder, but we see a moderately hyperemic gallbladder wall. It is a little bit thickened. There is some pericholecystic fluid around the gallbladder. If you look carefully, there is this focal area of disruption of the echogenic mucosa. Through that there is some fluid collecting between the liver and the gallbladder, which has formed a pericholecystic abscess. This is a patient who has an acute acalculous cholecystitis, and usually you see acalculous cholecystitis in patients who have a coexisting severe illness that can predispose them to acalculous cholecystitis. Usually sepsis or severe hypotension leads to wall ischemia of the gallbladder because of low flow states and then that can lead to gangrene and potentially perforation. This person had a perforated acute acalculous cholecystitis.

This is a different patient who had an unusual looking gallbladder. There is lots of echogenic material in the gallbladder, markedly echogenic. In this patient, this was a 44-year-old male who not only had echogenic material in the gallbladder, but he was positive for an acute cholecystitis and he had a coexisting coagulopathy. He ended up going on to CT. We see that his coagulopathy was caused by a cirrhotic liver, but within the gallbladder we see that there is very high density material within it. In this patient he has not only an acute cholecystitis, but it is a hemorrhagic cholecystitis, which is a rare complication of acute cholecystitis where because of the acute cholecystitis there is some mucosal breakdown of the wall and then that leads to hemorrhage into the gallbladder lumen. These patients usually have an underlying coagulopathy that leads to or predisposes them to bleeding within the gallbladder.

This is a different case, different patient. This case was given to me by my colleague Brooke Jeffrey, where there is echogenic material in this patient's gallbladder and this corresponds to very high density material on CT. This patient also had hemorrhagic cholecystitis.

This is a different patient who came in through the ER 37-year-old male with right upper quadrant pain and he has some very echogenic material in the gallbladder. It was really hard to tell if there was flow within that material. We have power Doppler, which should be more sensitive for slow flow states. Still kind of hard to tell if that is real flow or not, but when we put spectral tracings on it, there was this ever so slight subtle arterialized flow. It was really hard to tell for sure, and in fact the person who saw this case that this was just tumefactive sludge. But actually this turned out to be a gallbladder cancer. Something to always think about in the back of your mind, when you see echogenic material, could this be gallbladder cancer? This patient, he did not come back until two months later, at which point that gallbladder cancer had grown through the gallbladder wall and had invaded the adjacent liver.

Usually gallbladder cancer has three morphologic presentations. The most common is where you have a soft tissue arising from the gallbladder that infiltrates around the gallbladder and then kind of invades the adjacent liver. That is probably the most common imaging appearance. But occasionally you will have polypoid intraluminal masses usually over one centimeter in size. This is a different patient who has this markedly echogenic mass within the gallbladder with internal vascularity, which was actually a very large polypoid intraluminal mass. You can see that it is arising from the wall of the gallbladder and just completely filling the lumen of the gallbladder.

Occasionally gallbladder cancer can have diffuse or focal gallbladder wall thickening appearance. This is a patient with a large gallstone, but then at the fundus there is a soft tissue, which we see here. You wanna really look at that carefully and on transverse view we see that we have lost the normal echogenic mucosa and in fact there is some soft tissue that it has invaded into the adjacent liver. Whenever you lose the normal echogenic mucosa that is abnormal, you gotta figure out why that is. In this case, this was gallbladder cancer. We recommended CT for further staging. In this patient you can see that soft tissue invading the adjacent liver and six months later that had grown or progressed.

Gallbladder cancer is a very difficult diagnosis because often the presentation is quite vague. Patients have abdominal pain fever, sometimes they have weight loss or jaundice. Risk factors for gallbladder cancer include cholelithiasis cholecystitis, primary sclerosing cholangitis. We used to think that porcelain gallbladders increase the risk of gallbladder cancer, but more recently it has been found that the association is much lower than previously thought. It is only the calcifications that are diffuse mucosal calcifications that have a 7% association with gallbladder cancer. In any case, gallbladder cancer is a tough diagnosis. It is something that you wanna think about because you wanna try to catch it early. It really has a very poor prognosis with a five year survival rate of somewhere between two to 8%. Usually it will invade the liver like we see in this case. Then often it will spread to adjacent lymph nodes and spread intraperitoneally.

Different patient with echogenic material in their gallbladder in this patient. There is all of this stuff here, but if you look carefully, there is this line right in the middle of the gallbladder and that is the clue that we are looking actually at the gallbladder wall, which is so thick that it has it mimics intraluminal contents and it is actually obliterated the lumen of the gallbladder. Some of the thickest gallbladder walls you will see are in the setting of acute hepatitis A, which is what was the cause in this patient's marked gallbladder wall thickening that really looked like it was echogenic material in the gallbladder. This is the same patient CT where the gallbladder wall is just markedly thickened, obliterating the lumen.

Different patient with really marked gallbladder wall thickening. In this patient she was 33, had Sjogren's and lupus, and she came for an abdominal ultrasound because she had what was clinically an acute hepatitis and initially the sonographers that there was some sort of fluid or something between the liver and the gallbladder. But in fact that is the gallbladder wall that is so thick that it is, it kind of looked like a mass. This patient also had a CT that showed that the gallbladder wall was markedly thickened.

There is another entity that can cause really marked gallbladder wall thickening. Kind of unusual but dengue fever can give you very thickened gallbladder wall. It is sort of endemic in Southeast Asia and India. Actually there was a study done out of India where they had an epidemic of dengue fever and they found that the most common sonographic finding of dengue fever was a thickened gallbladder wall seen in 67% of patients. Other common findings included ascites pleural effusion and then less commonly hepatomegaly and splenomegaly.

Those are examples of kind of unusual, but instructive cases that presented with sonographic findings of echogenic material in the gallbladder.

Biliary Ductal Dilatation

Last case, last set of cases. This is a 54-year-old male with biliary ductal dilatation and he has both intra and extra hepatic biliary ductal dilatation. When you have that kind of imaging appearance, the thing that you wanna think about is, is there a distal obstructing mass or stone or maybe it is an infectious cholangitis, could there be a superimposed infection going on? Much less likely, but possible is a biliary tract IPMN.

In this patient, this ultrasound was read as intra and extrahepatic biliary ductal dilatation, but the cause was not really seen. But if you look at it carefully, all of those images I am showing you actually shows the abnormality and that is this little hyperechoic mass within the proximal CBD. He did go on to get an MR, and the MR was also read as negative except for the biliary ductal dilatation. But in retrospect you can see that same mass within the proximal common bile duct. He ended up going on to ERCP and then they went to surgery and at that point they asked me to go to the OR because they could not actually find the mass, they wanted an intraoperative ultrasound. I quickly looked at the ultrasound, I quickly looked at the MR and I too did not see the mass, but I was surprised, pleasantly surprised to see the mass on intraoperative ultrasound where it is clearly there. This is zoomed up, this is the common bile duct here. We can see that within it there is this large polypoid mass that is arising from the posterior wall of the biliary duct here and it is just floating within this biliary duct.

This was a biliary tract intraductal papillary neoplasm. Biliary tract IPMNs are IPMNs that originate from the biliary epithelium. Usually IPMNs we see in the pancreas all the time, very rarely from the biliary tract, they can have either solitary or diffuse intraductal growth. The reason why you get this biliary ductal dilatation is that these secrete a lot of mucin and then that is what distends the biliary system. These do need to be removed because they are a precursor of invasive carcinoma. This is the patient's ERCP image where we see the mass within the biliary system. This is the pathologic specimen showing that the IPMN.

Different patient with intra and extrahepatic biliary ductal dilatation. In this patient they have a large pancreatic head mass, pancreatic adenocarcinoma causing their biliary ductal dilatation. More of a classic cause.

Different patient with very marked intra and extrahepatic biliary ductal dilatation with some soft tissue extending from the distal CBD. In this patient, they also got a CT, I think that you can see the mass better on ultrasound, but you can see it on CT here. This was an ampullary adenocarcinoma.

Then a different patient with a dilated common bile duct. But in this patient they have a stent in place. They have a history of pancreatic cancer and they have sepsis. If you look at this carefully, not only is there biliary ductal dilatation, but there is some debris within the bile duct and there is wall thickening of the biliary duct. This patient not only has a dilated obstructed duct, but there is also a coexisting bacterial infection. These infections within the biliary system, they go into the biliary canaliculi, go retrograde and affect the hepatic veins, perihepatic lymphatics. These patients become very septic. They always wanna think about the possibility of a superimposed infection or acute cholangitis. When you see biliary duct dilatation, could there be a cholangitis?

Summary

In summary, we looked at some unusual cases that had relatively common sonographic presentations of echogenic portal triads, echogenic material in the gallbladder and biliary ductal dilatation. Thank you.