Obstruction
If there is an obstruction, we first look for gallstones in the bile duct. If there are no gallstones involved, we then look for strictures.
The differential diagnosis for a stricture is based on the location.
* A distal stricture is most likely the result of a distal cholangiocarcinoma, pancreatic carcinoma or pancreatitis.
* A stricture within the liver is likely due to gallbladder carcinoma or inflammatory strictures like PSC (Primary Sclerosing Cholangitis) or AIDS cholangiopathy.
* Metastatic disease can occur anywhere within the bilairy system.
No Obstruction
Once we have excluded obstruction, we have to think about nonobstructive biliary diseases like:
* Caroli disease
* Choledochal cyst
* Recurrent pyogenic cholangitis
* Primary sclerosing cholangitis