Hepatoid adenocarcinoma of the gallbladder

Hepatoid adenocarcinoma is a rare variant of extrahepatic adenocarcinoma which behaves like hepatocellular carcinoma in morphology and functionality. We present a rare case of hepatoid adenocarcinoma of the gallbladder which invades deeply the liver bed, in a 59-year-old woman. Histologically, most of the mass in the gallbladder was composed of cells with eosinophilic cytoplasm arranged in a trabecular pattern, which resembled hepatocellular carcinoma. The main differential diagnosis was hepatocellular carcinoma with invasion into the gallbladder. The gallbladder origin of the hepatoid adenocarcinoma was verified by the presence of foci of conventional adenocarcinoma, the recognition of high-grade dysplasia in the adjacent epithelium and the absence of cirrhosis.