Abstract
Intrahepatic bile duct adenoma is a rare benign epithelial tumor of the liver originated in bile duct cells which is rarely diagnosed from imaging methods and is incidentally detected at autopsy or surgery in many cases. We present a case of intrahepatic bile duct adenoma suggestive of hepatic metastasis of transverse colon carcinoma, together with a review of the literature.
A 74-year-old man who underwent left hemicolectomy for transverse colon carcinoma T4aN1M0 one year earlier was detected on CT to have a 7-mm low density area in the segment 8 of liver. EOB-MRI scan revealed faint high signal intensity on T2-weighted images, high signal intensity on diffusion-weighted images, and low signal intensity on hepatobiliary phase. Hepatic metastasis of the transverse colon carcinoma was diagnosed, and partial hepatectomy was performed. Histopathology revealed the tumor to be composed of growth of small tubular accumulation which was similar to bile duct. Immunochemistry showed the tumor cells to be positive for CK7 and negative for CK20. Intrahepatic bile duct adenoma was thus diagnosed.
Intrahepatic bile duct adenoma grossly mimics metastatic hepatic carcinoma as well and we have great difficulties in differential diagnosis. In making diagnosis of a hepatic tumor associated with malignant neoplasm, we should bear the possible existence of the disease in mind.
