Table 2.
Different forms of SSC with typical clinical and imaging findings
| Etiology | Cause | Clinical features | US/CT scan | ERCP/MRCP | References |
|---|---|---|---|---|---|
| Obstructive | − choledocholithiasis − neoplasia − gastroduodenal/hepatic arterial aneurysms − biliary strictures following surgical trauma |
may occur as recurrent/persistent bacterial cholangitis; increased bilirubin | dilated bile ducts; CBD stones; pancreatic or cholangiocarcinoma | intraductal stones; evidence of extrinsic compression | 3, 54 |
| Infectious | AIDS cholangiopathy: − cryptosporidiosis − CMV − microsporidiosis |
CD4+ <100/mm3; other opportunistic infections; HAART with restoration of immune function is the only treatment, antimicrobials are ineffective | intra- and/or extrahepatic bile duct dilation, hyperechoic echogenic nodules at the distal end of the CBD | papillary stenosis; typical beaded appearance is seen in 20% | 54, 81 |
| Immunologic | IgG4-related disease | serum IgG4 ↑; associated with type 1 autoimmune pancreatitis in 90%; responds to glucocorticoids | bile duct wall thickening; pancreatic enlargement or other findings of IgG4-related disease | dilation following long and continuous stricture (>10 mm); narrowing of the main pancreatic duct | 82, 83 |
| Ischemic | − post-OLT hepatic artery thrombosis − hepatic intra-arterial chemotherapy (TACE) |
liver-transplanted patients; liver metastases in patients with colorectal cancer; BCLC stage B hepatocellular carcinoma | dilated bile ducts; US may reveal bilomas | biliary casts; middle third of the common bile duct > hepatic duct confluence > intrahepatic bile ducts | 33, 54 |
| Drug-induced | − amoxicillin clavulanate − ketamine − celecoxib − others |
extrahepatic manifestations of intolerance; mostly reversible with discontinuation of the offending drug | dilated bile ducts; hydronephrosis is commonly seen in ketamine abuse | mainly right, left, and common hepatic duct involvement | 3, 27, 30 |
| Critically ill patients | ischemic bile duct injury | persistent cholestasis in patients surviving ICU treatment | US is normal in >50% of cases; CT and US may reveal intrahepatic bile duct dilation | sparing of the extrahepatic bile ducts; biliary casts; “pruned tree” appearance | 5, 65 |
BCLC, Barcelona Clinic Liver Cancer; CBD, common bile duct; CMV, cytomegalovirus; CT, computed tomography; ERCP, endoscopic retrograde cholangiopancreatography; HAART, highly active antiretroviral therapy; ICU, intensive care unit; MRCP, magnetic resonance cholangiopancreatography; OLT, orthotopic liver transplantation; SSC, secondary sclerosing cholangitis; TACE, transarterial chemoembolization; US, ultrasound.