MCQ – 70346

Correct Answer � D Explanation

Ans:D.)Primary Sclerosing Cholangitis

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Primary Sclerosing Cholangitis

• Primary sclerosing cholangitis (PSC) is a chronic cholestatic disorder, characterized by progressive fibrosis and destruction of extrahepatic and intrahepatic bile ducts of all sizes .
• Because the changes in the ducts are patchy, cholangiography, performed endoscopically or with the aid of magnetic resonance imaging (MRI), shows a characteristic beading in the affected segments of the biliary tree due to narrow strictures alternating with normal sized or dilated ducts.

MORPHOLOGY

• The characteristic features of PSC are different in the extrahepatic and large intrahepatic ducts than in the smaller ducts.
• The largest ducts have chronic inflammation with superimposed acute inflammation, very similar to the mucosal lesions of ulcerative colitis.
• These inflamed areas lead to narrowing of the larger ducts either because edema and inflammation narrows the lumen or because of subsequent scarring.
• The smaller ducts, however, often have little in the way of inflammation and show a striking circumferential fibrosis often referred to as onion skinning around an increasingly atrophic duct lumen.
• Eventually the lumen disappears altogether, leaving just a dense button of scar tissue, the virtually diagnostic tombstone scar.
• Because the likelihood of sampling such smaller duct lesions on a random needle biopsy is minuscule, diagnosis depends not on biopsy but on radiologic imaging of the extrahepatic and largest intrahepatic ducts.
• In response to duct loss, as in PBC, bile ductular proliferation, portal-portal septal fibrosis, and cirrhosis follow.
• The end-stage liver is therefore usually cirrhotic and green. Biliary intraepithelial neoplasia may appear and be a harbinger of cholangiocarcinoma