Markedly elevated serum CA 19-9 levels in association with a benign biliary stricture due to primary sclerosing cholangitis.

We report on the case of a 55-year-old man with long-standing ulcerative colitis who developed jaundice. This led to a diagnosis of primary sclerosing cholangitis being made, with a dominant stricture in the common bile duct. Serum CA 19-9 was initially markedly raised at 26,321 U/mL but fell promptly into the normal range after stenting of the stricture. Long-term follow up of this patient has failed to show evidence of cholangiocarcinoma. We conclude that serum CA 19-9 levels need to be assessed in the clinical context of biliary obstruction and should ideally be measured after relief of that obstruction, as it may be falsely elevated due to benign biliary strictures.