Patho Exam 3- Biliary and Pancreas

What are choledochal cysts?

Congenital cystic dilation of bile ducts

What populations are more likely to have choledochal cysts?

Young girls; most prevalent in Asia

What are the clinical sxs for choledochal cysts?

Intermittent palpable abdominal mass, pain, fever, intermittent jaundice, failure to thrive, possible increased bilirubin

What are the 5 types of choledochal cysts?

1. Fusiform cystic dilation of CBD

2. Diverticulum from the CBD

3. Invagination of the CBD into the duodenum

4. Intrahepatic and extrahepatic dilation

5. Caroli’s disease

What is the most common type of choledochal cyst?

Type 1- Fusiform cystic dilation of CBD

Which type of choledochal cyst is rare?

Type 2- Diverticulum from the CBD

Which type of choledochal cyst involves dilation of the very distal CBD, resulting in a choledochocele?

Type 3- invagination of the CBD into the duodenum

Which type of choledochal cyst involves multifocal dilation of intra & extrahepatic bile ducts?

Type 4- intrahepatic and extrahepatic dilation

Which type of cheldochal cyst involves multifocal segmental dilation of intrahepatic ducts? This type is not considered a true choledochal cyst.

Type 5- Caroli’s disease

What are the US findings of choledochal cysts?

Cystic dilation of the biliary system, dilations may contain sludge, stones, or solid neoplasms; dilations can be large enough that connection to bile duct not recognized

What do choledochal cysts cause risk of?

Cholangiocarcinoma

What is Caroli’s disease caused by?

In-utero malformation of the ductal plates (cells that give rise to the intrahepatic ducts)

What type of dilation is more commonly seen with Caroli’s disease?

Saccular

What does Caroli’s disease result in?

Biliary stasis, stone formation, cholangitis, sepsis

What are the sxs of Caroli’s disease?

Crampy pain, fever, intermittent jaundice

What is the important sign that differentiates Caroli’s disease from other cysts within the liver?

Central dot sign- corresponds to PV surrounded by dilated bile ducts; will show blood flow on color Doppler

What is biliary atresia?

Rare congenital obliteration of one or more components of the bile ducts

What does biliary atresia cause?

Abnormal accumulation of bile in the liver, which causes jaundice and scarring of the liver

When do the sxs for biliary atresia present?

Shortly after birth (2-6 weeks of life)

What are the sxs of biliary atresia?

Persistent jaundice, pale stools and dark urine, failure to thrive, portal HTN, cirrhosis, liver failure

What are the US findings of biliary atresia?

Biliary dilation may or may not be present, SMALL GB, portal HTN, triangular cord sign

What does the triangular cord sign represent in pts with biliary atresia?

The fibrous ductal remnant of the extrahepatic bile duct

What is the treatment for biliary atresia?

No cure but attention to nutritional needs and special diet are essential; surgery; liver transplant

What surgery can be used to treat biliary atresia?

Hepatoportoenterostomy- portion of small intestine used to form a conduit to allow bile drainage

How is the CBD measured?

Measure lumen from inner wall to inner wall; make sure calipers perpendicular to the duct; measurement must be EXTRAHEPATIC

What is the one millimeter per decade rule for CBD measurements?

The CBD diameter increases 1 mm per decade after 50 y/o. For example, a 60 y/o can be expected to have a CBD measuring 6 mm

What is a normal measurement for the CBD?

5mm or less

What is an equivocal measurement for the CBD?

6-7 mm

What is an abnormal dilated measurement of the CBD?

8mm or greater

Is it ok for a pt’s CBD to measure 10 mm if they have received a cholecystectomy?

YES b/c they had their GB removed, which makes the CBD act as a reservoir for bile storage

What are the 2 most common biliary obstructions?

Choledocholithiasis and pancreatic adenocarcinoma (at head of pancreas)

What part of the CBD do we see the most biliary obstructions in?

Distal CBD

What are the US signs of intrahepatic duct dilation?

Too many tubes, parallel channel sign, shotgun sign

What is the criteria to differentiate intrahepatic bile ducts from PVs?

Parallel channel or shotgun signs, bile ducts are more tortuous than portal veins, stellate confluence of dilated ducts “spokes of wheel”, dilated bile duct in liver periphery

What is painful jaundice caused by?

Biliary obstruction due to stones

What is painless jaundice caused by?

Suggestive of malignant biliary obstruction

What happens to the biliary tree when there is a distal CBD obstruction?

The entire system, including the gallbladder distends

What happens to the biliary tree when there is an obstruction in the common hepatic duct?

Only the CHD and intrahepatic ducts dilate- GB is contracted

What happens to the biliary tree when there is an obstruction in the junction of the RT and LT hepatic ducts?

Only intrahepatic ducts dilate- GB is contracted

What is choledochalithiasis?

Stones in bile ducts

What is the rare type of choledochalithiasis?

Primary- formation of stones WITHIN the bile ducts

What is the common type of choledochalithiasis?

Secondary- stones in the CBD have MIGRATED from the GB

What are the sxs of choledochalithiasis?

RUQ or epigastric pain, jaundice

What can cause choledochalithiasis?

Sclerosing cholangitis, caroli’s, parasitic liver infection, sickle cell disease, prior biliary surgery (all of these cause stricture or dilation, leading to bile stasis)

What do CBD stones look like on US?

Rounded, hyperechoic intraductal stones, posterior shadowing; dilated ducts proximal to obstruction; dilated GB

Where are the majority of CBD stones located?

Distal CBD

What do intrahepatic bile duct stones look like on US?

Same as CBD stones; ducts filled with stones may appear as a bright echogenic linear structure with or without posterior shadowing; smaller stones may not have posterior shadowing; dilated ducts proximal to obstruction

What structures can be mistaken for stones in the bile ducts?

Blood clots, papillary tumors, biliary sludge (all do not shadow)

What can be seen as linear echogenic foci with shadowing in the porta hepatis, usually in patients that receive a cholecystectomy? These can be mistaken for stones in the bile ducts.

Surgical clips; can be distinguished by lack of ductal dilation and absence of GB

What are the treatments for choledochalithiasis?

Surgical retrieval, endoscopic retrieval, fragmentation to reduce size, chemical dissolution

What type of syndrome is related to obstruction of the CHD by a stone impacted in the cystic duct?

Mirizzi syndrome

What can happen as a result of Mirizzi syndrome?

Acute cholecystitis, cholangitis, pancreatitis, biliary fistulas (impacted stone erodes into CHD causing holes in the bile duct)

What does Mirizzi syndrome look like on US?

Impacted stone in cystic duct causes biliary dilation in CHD and intrahepatic ducts, edema, acute/chronic cholecystitis

What is pneumobilia?

Air or gas within the biliary tree

What is pneumobilia associated with?

Biliary intervention, emphysematous cholecystitis, biliary/GI tract fistula (hole)

What does pneumobilia look like on US?

Posterior dirty shadowing, bright echogenic linear structures, reverb artifact (ring down), movement of air bubbles after changing position

What is blood in the bile or bile ducts called?

Hemobilia

What is the most common cause of hemobilia?

Medical examination or treatment

What does hemobilia look like on US?

Echogenic/mixed echogenicity, blood clot may be mobile, conforms to shape of duct and may extend to GB, acute hemorrhage appears as fluid with some internal echoes

What is the term for inflammation of the bile ducts due to infected bile?

Cholangitis

What are the 4 types of cholangitis?

Acute bacterial, recurrent pyogenic, HIV cholangiopathy (AIDS cholangitis), sclerosing

What is the most common cause of acute bacterial cholangitis?

Choledocholithiasis

Is acute bacterial cholangitis a medical emergency?

YES- can lead to SHOCK

What are the US findings for acute bacterial cholangitis?

CBD and biliary tree dilated, bile duct stones and intraductal sludge, bile duct wall thickening, hepatic abscesses

What is the treatment for acute bacterial cholangitis?

Abx or dilation of ductal stricture

What is recurrent pyogenic cholangitis (RPC)?

Multiple recurrent episodes of biliary obstruction, stasis, stone formation

What population is recurrent pyogenic cholangitis seen the most in?

SE/East Asia

What segment of the liver is most commonly affected by recurrent pyogenic cholangitis?

Lateral left lobe

What are the acute sxs of recurrent pyogenic cholangitis?

Sepsis

What are the chronic complications of recurrent pyogenic cholangitis?

Severe atrophy (death) of affected liver segment

What are the US findings for recurrent pyogenic cholangitis?

Dilated ducts filled with sludge/stones confined to 1 or more segments of the liver; multiple echogenic liver masses within extremely dilated ducts; SEGMENTAL ATROPHY

What type of cholangitis is a chronic inflammatory disease process that affects the ENTIRE biliary tree?

Primary sclerosing cholangitis (SC)

Is there a known cause for sclerosing cholangitis?

NO; may be related to autoimmune

What happens in sclerosing cholangitis?

Scarring and destruction of intra and extrahepatic bile ducts

What can sclerosing cholangitis lead to?

Biliary strictures, cholestasis (bile stops excreting), biliary cirrhosis, portal HTN, liver failure

What population is most affected by sclerosing cholangitis?

Men (avg 39 y/o)

What are the sxs for sclerosing cholangitis?

Asymptomatic in early stages, slow to progress

What is a key feature of sclerosing cholangitis found on US?

Bile duct wall thickening causing narrowed lumen

What can late stage sclerosing cholangitis cause and what can be done to treat it?

Cirrhosis; liver transplant- SC may recur in transplanted liver

What is AIDS cholangitis?

Inflamed biliary tree in late stages of HIV infection

What type of infection is AIDS cholangitis?

Opportunistic

What are the sxs for AIDS cholangitis?

SEVERE RUQ/epigastric pain, elevated ALP with NORMAL bilirubin

What are the sxs of AIDS cholangitis?

Similar to sclerosing cholangitis except caused by HIV

What is the parasitic roundworm that can be found in the biliary tree?

ascariasis

How does ascariasis enter the biliary tree?

Fecal-oral route; starts in bowel and enters biliary tree through ampulla of vater

What is the population most affected by ascariasis?

Young children in tropical areas with low hygiene and sanitation

What are the sxs for ascariasis?

Asymptomatic, biliary colic (RUQ pain), cholangitis, acalculous cholecystitis, pancreatitis

What medication can be used to kill mature worms that cause ascariasis?

Mebendazole

What does ascariasis look like on US?

Parallel echogenic lines in bile ducts, movement of worm during scan confirms, spaghetti like appearance

What is the malignant neoplasm that arises from the EPITHELIUM of the bile ducts?

Cholangiocarcinoma

What country has an higher incidence of cholangiocarcinoma?

Thailand

What is the most common risk factor for cholangiocarcinma in the West?

Primary sclerosing cholangitis

What is the most common risk factor for cholangiocarcinoma in populations outside of the West?

Recurrent biliary infections and stone disease

90% of cholangiocarcinomas are ___.

Adenocarcinomas

What are the unique sxs of cholangiocarcinoma?

Pruritis (itching), anorexia, biliary colic, palpable mass

What are the US findings for cholangiocarcinoma?

Biliary dilation WITHOUT obstruction, non-union of left and right ducts, irregular soft tissue mass that extends into ducts, tumor extension adjacent to vasculature, lymph node extension to porta hepatis

What is the least common type of cholangiocarcinoma (10%)?

Intrahepatic (peripheral)- arises within hepatic parenchyma

What is the most common type of cholangiocarcinoma (60%)?

Hilar (Klatskin’s)- located at porta hepatis

What type of cholangiocarcinoma arises in the distal extrahepatic ducts (30%)?

Distal

What is the 2nd most common primary malignancy of the liver?

Intrahepatic cholangiocarcinoma