Biliary cystadenoma with mesenchymal stroma of the liver: correlation between unusual MR appearance and pathologic findings.

We reported a case of the biliary cystadenoma of the liver. The cystic mass had lobulation and septation and showed marked hyperintensity on T1-weighted images and hypointensity on T2-weighted images; MR findings were very unusual for cystadenoma. The content of the cystic mass was jelly-like, thick mucinous fluid without intracystic hemorrhage. We concluded that these unusual signal intensities of the cyst were due to hyperproteinous mucinous fluid.