Hepatoid carcinoma of the pancreas combined with neuroendocrine carcinoma.

Hepatoid carcinoma is a primary extrahepatic carcinoma whose morphology, immunohistochemistry, and behavior are similar to those of hepatocellular carcinoma. The most common sites of extrahepatic carcinoma are the stomach and ovary, but nine cases of hepatocellular differentiation of the pancreas have been reported in the literature. We report another case of hepatoid carcinoma of the pancreas that was associated with the development of a pancreatic endocrine carcinoma in a 46-year-old man. Serum alpha-fetoprotein (AFP) was elevated to 262.49 IU/mL and radiological examinations revealed a mass measuring 7.5 cm in diameter in the head of the pancreas. He underwent a conventional Whipple operation, and light microscopy showed adenocarcinoma that was immunopositive for AFP, hepatocyte antigen, cytokeratin, chromogranin, synaptophysin, and alpha-1 antichymotrypsin. Although hepatoid differentiation was not shown unequivocally histologically, other immunohistochemistry findings supported the diagnosis of hepatoid carcinoma combined with neuroendocrine carcinoma. The patient was healthy and had no evidence of recurrence at 4 months after the surgery. This report describes why hepatoid carcinoma should be considered as a differential diagnosis of a pancreatic mass, especially when serum AFP is elevated.