Diagnosing Small Duct Primary Sclerosing Cholangitis—A Rarer Variant of a Rare Disease: Challenges and Role of Liver Biopsy

Primary sclerosing cholangitis (PSC), a disease of unknown etiology, is diagnosed on the clinical and biochemical findings of cholestasis combined with the characteristic findings seen on cholangiography. Small duct cholangitis is a variant of the PSC spectrum with distinct clinical course and outcome. We present two cases of small duct PSC, which are presented with the clinical and biochemical features of cholestasis but without typical positive findings on cholangiography. A liver biopsy was attempted, which confirmed sclerosing cholangitis. Upon diagnosis, both the patients were prescribed ursodeoxycholic acid at a dose of 15 mg/kg body weight/day and liver biochemistry was followed up after 3 months, which revealed biochemical improvement. Being an uncommon variant of this “not so common” disease spectrum, small duct PSC often poses a diagnostic dilemma with its presentation due to the clinical and cholangiographic mismatch. The cases remind that a negative cholangiography does not rule out the PSC spectrum.