Special thanks to my GI attending, Dr. Jessica Tracht, for her helpful tips and tricks!
(Pictures/examples will be uploaded shortly)
The Basics of Biliary pattern pathology:
Something is obstructing or causing damage the bile ducts.
Must see reactive bile ductules (increased number of irregular ducts, often mixed with neutrophilic inflammation).
Assess the native bile ducts- if they are missing (ductopenia), damaged, or inflamed bile ducts, this is likely a biliary process.
The presence of cholestasis also helps indicate a biliary process, but it isn’t always seen. NOTE: When cholestasis injures hepatocytes this is called ‘feathering degeneration’ as opposed to ‘ballooning degeneration’ in steatohepatitis and should be noted in the comment if present.
If fibrosis occurs it will be portal based and in a “jigsaw” type pattern.
Alkaline phosphatase is usually elevated.
Copper accumulates in the peri-portal regions of biliary processes, so a copper stain can be helpful in to determine if this is the etiology of injury (Note: This stain takes >24 hours to perform and copper will accumulate in cirrhotic livers despite the mechanism of injury so it wouldn’t be helpful with advanced fibrosis).
Differential diagnosis of a biliary pattern in liver:
Obstruction
-Portal edema with marked ductular reaction.
-Bile duct inflammation can be present. If there is neutrophilic inflammation of native ducts (not just as part of a ductular reaction) this could be a sign of ascending cholangitis. This is life threatening and the patient will likely be very sick.
-Cholestasis
-Bile duct injury (+/-)
Immune mediated cholangiopathy
Common Features suggesting an immune process:
Bile duct loss
Bile duct injury
Bile duct inflammation
Bile ductular reaction
Cholestasis (+/-)
Specific features of Primary Biliary Cholangitis (PBC)
Bile duct inflammation and damage
Florid duct lesion
Duct loss
Granulomas (+/-)
Can have some degree of interface activity
Nodular regenerative hyperplasia.
Positive AMA
Note: this is no longer referred to a primary biliary cirrhosis
Specific features for Primary Sclerosing Cholangitis (PSC)
Periductal fibrosis, especially in medium and larger sized ducts
Small duct loss (can be the only feature seen)
Bile duct damage
Will have distinctive radiologic features on MRCP
Example Sign Out
FINAL DIAGNOSIS:
Liver, native, core biopsy:
Bile ductular reaction, focal bile duct injury, and mild cholestasis; features suggestive of a biliary process.
Mild portal fibrosis.
See comment.
PATHOLOGIST'S COMMENT:The specimen consists of a core liver biopsy with 11 portal tracts available for evaluation. The portal tracts contain a minimal to mild inflammatory infiltrate consisting primarily of lymphocytes with rare plasma cells. There is no significant interface activity. A bile ductular reaction is present in a majority of the portal tracts. The native bile ducts appear intact, but with focal duct injury present. There is mild lobular inflammation. Mild cholestasis is seen with scattered feathering hepatocyte degeneration. No significant hepatocyte dropout or necrosis is present. A trichrome stain highlights mild portal fibrosis. An iron stain is negative. A PAS-D stain is negative for PAS positive globules.
The patient’s clinical history of negative viral serologies with elevated AMA and alkaline phosphatase is noted. Overall, these features are relatively non-specific, but are suggestive of a biliary process. The differential diagnosis most likely includes an immune mediated cholangiopathy, and given the elevated AMA, primary biliary cholangitis (PBC) would be favoared. However, no classic features of PBC, or primary sclerosing cholangitis are present. An obstructive process or vascular flow abnormality can also not be completely excluded. Clinical correlation is recommended.
Continue reading about other patterns of pathology seen in the medical liver biopsy...