A case of an alpha-fetoprotein-producing intrahepatic cholangiocarcinoma.

Alpha-fetoprotein is a well-known marker of hepatocellular carcinoma. Alpha-fetoprotein-producing intrahepatic cholangiocarcinoma is rare. This report detailed our experience with such a case and reviewed the relevant literature. A 71-year-old man underwent dynamic computed tomography, which revealed a 40-mm hepatic mass in S6 with early arterial phase enhancement and delayed phase washout. Analysis of tumor markers revealed elevated alpha-fetoprotein levels. Positron emission tomography-computed tomography indicated a maximum standardized uptake value of 3.70. Presuming hepatocellular carcinoma, we performed a laparoscopic subsegmentectomy of S6. However, immunohistochemical examination revealed that the tumor was cytokeratin 7- and cytokeratin 19-positive, whereas the Hepatocytes and glypican-3 were negative, with some cells expressing alpha-fetoprotein, leading to a final diagnosis of alpha-fetoprotein-producing intrahepatic cholangiocarcinoma. After surgery, the patient was followed up without postoperative adjuvant chemotherapy at his request. Six months later, the patient's alpha-fetoprotein level increased again, and computed tomography revealed multiple intrahepatic and lung metastases. Chemotherapy was subsequently initiated. Six courses were administered; however, the disease gradually worsened, and the patient died 13 months after surgery. Differentiating between hepatocellular carcinoma and intrahepatic cholangiocarcinoma is crucial because of divergent postoperative treatments. Although rare, alpha-fetoprotein-producing intrahepatic cholangiocarcinoma should be considered in liver tumors, even with isolated alpha-fetoprotein elevation.