primary sclerosing cholangitis

WKP

PO

Types

 neonatal sclerosing cholangitis
 auto-immune sclerosing cholangitis

Microscopy synopsis

 "onion skin" fibrosis around affected medium sized bile ducts;

• smaller ducts rarely affected (except in small duct primary sclerosing cholangitis), meaning biopsy sampling rarely demonstrates this finding

 progressive atrophy of bile duct epithelium and obliteration of the lumen, leaving a fibrous scar
 ductular reaction and cholestasis may occur
 portal inflammatory infiltrate is typically mild and limited to biliary epithelium and portal tracts, though largest ducts may show increased infiltrate
 extravasated bile

• may elicit xanthomatous or granulomatous response

 portal edema and portal fibrosis may be seen secondary to obstruction of larger ducts

Primary sclerosing cholangitis cirrhosis shows the typical biliary jigsaw pattern

Cholangiocarcinoma may occur in primary sclerosing cholangitis, preceded by intestinal metaplasia and biliary intraepithelial neoplasia (Am J Surg Pathol 2010;34:27)

Several staging systems exist, with the Ludwig system the most commonly used (Hepatology 2017;65:907):
 cholangitis / portal hepatitis
 periportal fibrosis or periportal hepatitis
 bridging fibrosis or bridging necrosis
 cirrhosis