Bile duct hamartoma diagnosed as hepatocellular carcinoma based on preoperative imaging findings and treated with surgical resection: a case report

Abstract

The patient was a 73-year-old man with a history of chronic hepatitis C. Two liver tumors were incidentally discovered during an examination for proteinuria. The tumor marker PIVKA-2 was elevated, with a value of 1003 mAU/mL. On dynamic CT, the S8 tumor (42mm) showed early enhancement and washout during the equilibrium phase, while the S6 tumor (10mm) exhibited early enhancement but poor washout. EOB-MRI revealed low-signal areas on T1-weighted images, high-signal areas on T2-weighted and diffusion-weighted images, and early enhancement with low-signal areas in the hepatocellular phase during dynamic contrast. Based on these findings, hepatocellular carcinoma (HCC) was diagnosed at both sites followed by two partial hepatectomies. Pathological examination revealed that the S8 tumor was HCC, while the S6 tumor was diagnosed as a bile duct hamartoma, characterized by a cluster of dilated bile ducts with bile accumulation. Therefore, it should be noted that bile duct hamartomas are potential candidates for early contrast enhancement of the liver.