Carcinoma of the stomach with hepatocyte differentiation (hepatoid adenocarcinoma).

A case of hepatoid adenocarcinoma of the stomach is reported, and the literature is reviewed. The stomach is one of the most common sites in which hepatoid adenocarcinomas have been detected. Of the 59 cases reviewed from the literature (including the current case), a 2:1 male predominance was noted, and the serum alpha-fetoprotein level was almost always increased. All patients were adults, and most had evidence of metastases at the time of resection. Prognosis seems less favorable than that associated with the more common intestinal type of adenocarcinoma of the stomach. Hepatoid adenocarcinomas typically show periodic acid-Schiff-positive, diastase-resistant intracytoplasmic globules, which are demonstrated to be positive with antibodies to alpha-fetoprotein. The tumor cells resemble liver cells, and rare cases, including our own, have evidence of bile production. In our case, messenger RNA for albumin, unique to liver cells, was demonstrated by in situ hybridization of the tumor cells.