As previously highlighted by Case 2, one of the diagnostic dilemmas with PSC is that it can often be challenging to distinguish from secondary causes of sclerosing cholangitis and malignancy. Causes of secondary sclerosing cholangitis must be excluded before a diagnosis of PSC can be established. The most commonly described secondary causes include stone disease, infection, pancreatitis, and surgical/procedural trauma. A more comprehensive list of differential diagnoses of PSC is provided in Table 2 .
Another caveat is the fact that the presence of cirrhosis may interfere with interpretation of ERCP/MRCP findings. In particular, subtle intrahepatic ductal changes in PSC can be difficult to distinguish from biliary tract changes seen with cirrhosis, and although a liver biopsy can be helpful, history alone may be the only suggestion of PSC. A high index of suspicion will be necessary to make an assertive diagnosis in this setting, keeping in mind that most cases of PSC occur in patients with inflammatory bowel disease.
Cite this: Primary Sclerosing Cholangitis -- Approach to Diagnosis - Medscape - Apr 25, 2007.