Adenoendocrine cell carcinoma of the gallbladder producing a high level of alpha-fetoprotein.

We present the case of a 78-year-old Japanese woman with adenoendocrine cell carcinoma of the gallbladder accompanied by a high serum alpha-fetoprotein level. The patient visited our hospital with a complaint of a large mass in the right hypochondrium. Ultrasonography and computed tomography revealed multiple large hepatic tumors, swelling of lymph nodes in the hepatic hilum and para-aortic regions, and a slightly irregular gallbladder wall. The serum alpha-fetoprotein level was 157,428 ng/mL. We initially suspected scirrhous hepatocellular carcinoma, sarcomatous hepatocellular carcinoma, biliary tract cancer, or pancreatic cancer. However, the hepatic tumor biopsy was histologically diagnosed as undifferentiated adenocarcinoma. Immunohistochemical analysis demonstrated that the tumor was positive for cytokeratin 19, focally positive for cytokeratin 7, but negative for hepatocyte paraffin 1 and cytokeratin 20, suggestive of biliary tract carcinoma. Although the patient received a course of hepatic arterial infusion chemotherapy with cisplatin, she died 2 months after admission. Histopathological examination at autopsy revealed that the hepatic tumor was adenoendocrine cell carcinoma of the gallbladder, which was positive for cytokeratin 19, focally positive for cytokeratin 7, chromogranin A, synaptophysin, and weakly positive for alpha-fetoprotein. Labeling index of Ki-67 was 28 %. Interestingly, this was the first case report of adenoendocrine cell carcinoma of the gallbladder that produced a high level of alpha-fetoprotein, which hampered correct diagnosis before autopsy.