Hepatoid adenocarcinoma of the stomach: a case report

A patient with primary gastric carcinoma showing a high level of serum a-fetoprotein (AFP) (368 ng/ml) is described. Subtotal gastrectomy was performed, and a month after surgery the level of serum AFP fell rapidly to within normal limits. Histologically, two types of cells coexisted in the tumor: medullary-type cells resembling trabecular-type hepatocellular carcinoma, and moderately differentiated adenocarcinoma cells. The cells of the former type were arranged mostly in a trabecular pattern with bile granules, but also showed a scirrhous pattern in a restricted area. Immunohistochemistry demonstrated that both types of tumor cells stained positively for AFP. This tumor, which should be classified as a hepatoid adenocarcinoma of the stomach, is of interest because of its rarity, bile secretion (indicating marked differentiation toward a hepatocyte form), and two cellular arrangements-trabecular and scirrhous.