Intrahepatic Cholangiocarcinoma Coexisting With Multiple Bile Duct Adenoma Treated as Liver Metastasis from a Pancreatic Neuroendocrine Tumor.

Abstract

Bile duct adenomas (BDA) may be precursor lesions of small duct-type, including mass-forming type intrahepatic cholangiocarcinoma (ICC). A 68-year-old woman was transferred to our facility for the treatment of a liver tumor, possibly metastasized from a pancreatic neuroendocrine tumor. Finally, two liver tumors were resected and histopathologically diagnosed as "BDA" and "ICC with a BDA-like component". In the BDA-like component, the MUC6 positive rate was notably lower and the Ki-67 positive rate was higher than the other BDAs and ICC component, respectively. The doubling time of the tumor volume in BDA was very long but was shortened (1,510 and 719 days). Distinct enlargement of the tumor and appearance of enhancement through diagnostic imaging was useful in diagnosing the transformation from a BDA to an ICC. An "adenoma-carcinoma sequence" may exist in the transformation process from a BDA to an ICC.