Hepatoid Adenocarcinoma of the Stomach: Biological Significance of Hepatic Transdifferentiation in Adenocarcinoma Cells

Hepatoid adenocarcinoma is an extrahepatic carcinoma with functionally and structurally distinctive foci of hepatocellular differentiation. The usual presence of adenocarcinoma indicates the emergence of hepatocellular transdifferentiation from adenocarcinoma cells. Hepatoid adenocarcinoma most commonly occurs in the stomach, but other gastrointestinal and genitourinary organs are also common sites of origin. Master transcriptional regulators, particularly liver-enriched nuclear factors, might be involved in the transdifferentiation process, as well as in the biology of hepatoid adenocarcinoma tissues.