Lesion/Condition Name: Primary Sclerosing Cholangitis
What is it? Primary Sclerosing Cholangitis, PSC, is a chronic, progressive liver disease caused by inflammation and scarring of the bile ducts. The subsequent impedance of bile flow can ultimately lead to liver cirrhosis, liver failure and liver cancer.
Associations/Predisposing Factors: PSC is usually an idiopathic condition, although it is believed to be autoimmune in etiology. PSC can be seen in patients with chronic pancreatitis, inflammatory bowel disease or sarcoidosis.
Demographics: PSC is more common in men, with a female to male ratio ranging from 0.2 to 0.4. Patients usually present between 20-40 years of age; however, PSC is being increasingly recognized as a cause of chronic liver disease in children.
Histology: PSC histologically is characterized by periductal fibrosis, together with portal edema, duct and ductular proliferation, portal inflammation and cholestasis.
Radiology: The cholangiographic findings depend on the stage of the disease process. Early in the course of the disease, randomly distributed intrahepatic strictures alternating with normal or slightly dilated segments produce a beaded appearance. As the fibrosing process worsens, strictures increase and the ducts become obliterated, and the peripheral ducts cannot be visualized to the periphery of the liver at ERCP, producing a â€śpruned treeâ€ť appearance. With further progression, strictures of the central ducts prevent peripheral ductal opacification at ERCP. The key cholangiographic features of PSC are randomly distributed annular strictures out of proportion to upstream dilatation, which probably reflect periductal inflammation and fibrosis that prevent the ducts from dilating.
Radiologic Differential Diagnosis: Secondary sclerosing processes that resemble PSC at cholangiography include ascending cholangitis as a result of strictures, stones, or bile duct anomalies, oriental cholangiohepatitis, AIDS-related cholangitis, and ischemia. A variety of nonsclerosing processes can also mimic PSC at cholangiography, including hepatic metastases, cirrhosis, polycystic liver disease, multifocal hepatoma, and cholangiocarcinoma.
How is this Diagnosis usually Confirmed: Patients usually present with fatigue, pruritis, and jaundice although many individuals are asymptomatic. Findings associated with sclerosing cholangitis include hepatomegaly, splenomegaly, anorexia and weight loss, or repeat episodes of cholangitis. Patients classically have abnormal liver function tests and a liver biopsy consistent with sclerosing cholangitis is also useful in the diagnosis. Many patients with PSC have evidence of autoantibodies. Approximately 80% of patients have perinuclear anti-neutrophil cytoplasmic antibodies, and antinuclear antibodies and anti-smooth muscle antibody are found in 20%-50% of PSC patients. Individuals may have evidence of PSC on multiple imaging modalities as described above.
Prognosis and Treatment: PSC is a progressive condition with several possible complications, including; ascites, varices, biliary cirrhosis, liver failure, persistent jaundice, or recurrent cholangitis. Patients diagnosed with PSC have an increased risk of developing cholangiocarcinoma and should be checked regularly with hepatic imaging and function testing. One study showed the average survival time from time of diagnosis to be approximately 25 years, and the median time until either death or liver transplantation to be approximately 10 years.