A case of intrahepatic biliary cystadenoma with mesenchymal stroma is reported. The tumor was associated with strikingly elevated serum and intracystic levels of the tumor-associated antigen CA19-9. Two months after surgical enucleation, serum CA 19-9 levels returned to normal.
Schoonbroodt, D., Horsmans, Y., Gigot, J.-F., Rahier, J., & Geubel, A. (1994). Biliary cystadenoma of the liver with elevated CA 19-9. Liver, 14(6), 320-322. https://doi.org/10.1111/j.1600-0676.1994.tb00096.x (Original work published 1994)