Elevated serum CA 19-9 level mimicking pancreaticobiliary carcinoma from a hepatic abscess: case report and literature review.

Serum levels of the tumor marker CA 19-9 are widely utilized in the diagnosis and monitoring pancreatic and biliary malignancies. However, serum levels of CA 19-9 have also been reportedly elevated in non-malignant conditions. Here, we present the rare case of a 65-year-old woman with a history of gallbladder malignancy who was found to have a new hepatic lesion on surveillance CT with an associated elevation in CA 19-9 to 5,866 U/mL. Drainage of the lesion and treatment with antibiotics resulted in a rapid decline in CA 19-9 levels, indicating that the elevation in CA 19-9 was due to a benign hepatic lesion. We review eight similar reported cases of CA 19-9 elevations due to benign hepatic abscesses, thereby highlighting a need to interpret the tumor marker with caution.