A 65-year old man with background primary sclerosing cholangitis (PSC) diagnosed 5 years previously presented with worsening jaundice, pruritus and weight loss. His liver function tests confirmed cholestatic jaundice. His Ca 19-9 levels were raised. Cross-sectional imaging with a CT suggested dilatation of the intrahepatic biliary system. A stricture was also noted in the extra-hepatic common bile duct. This image reveals the extra-hepatic common bile duct stricture. A cholangiogram confirmed features typical of PSC. There was significant and typical narrowing of the intra-hepatic bile ducts with sacculation and beading. A stricture was noted in the mid-third of the common bile duct with dilatation of the common hepatic duct. His distal common bile duct also looked narrowed with classical beading and sacculation.
We performed a cholangioscopy to obtain an endoscopic and histological diagnosis of the bile duct stricture. Cholangioscopy demonstrates a normal looking bile duct wall with a smooth stricture. A small saccule is noted adjacent to the stricture. Biopsies are taken from the stricture. Some mucin and debris are also seen around the stricture. There is no endoscopic evidence of malignancy around the stricture such as abnormal tissue or neo-vascularization.
Histology reveals biliary epithelium and some inflammatory exudate. Mild nuclear polymorphism is noted with no evidence of dysplasia or malignancy.
The diagnosis of a dominant stricture in PSC is difficult. A dominant stricture may be seen in upto 60% of patients and may be extra or intra-hepatic. A PSC stricture is called dominant when it becomes symptomatic, presenting as mechanical biliary obstruction. Jaundice, pruritus, ascending cholangitis or malabsorption may occur as a consequence of a dominant stricture. The incidence of cholangiocarcinoma in PSC is up to1.5% per annum with a 10-15% lifetime risk. It is difficult to differentiate a dominant stricture from early cholangiocarcinoma and therefore, tissue diagnosis of a dominant stricture in the form of cytology or histology is crucial.
The learning points from this presentation are that the evaluation of a suspected dominant stricture in PSC is not only important but evaluating biliary strictures in PSC during ERCP can be very difficult. Often, direct visualization with cholangioscopy is possible and is a complementary tool to ERCP and cross-sectional imaging. Tissue diagnosis and cytology are critical in excluding cholangiocarcinoma within a PSC stricture. The differentiation of a stricture as benign or malignant should be based on a multitude of tests and cholangioscopy, as demonstrated may improve the diagnostic yield.
Shyam Menon, MD, MRCP, University Hospital Aintree
Venkata Lekharaju, MRCP, University Hospital Aintree
Monica Terlizzo, MD, University Hospital Aintree
Richard Sturgess, MD, University Hospital Aintree