Hepatoid adenocarcinoma of the stomach with liver metastasis mimicking hepatocellular carcinoma: a case report

INTRODUCTION: Hepatoid adenocarcinoma is a special type of extrahepatic alpha-fetoprotein-producing adenocarcinoma, which has a morphologic similarity to hepatocellular carcinoma. We report a patient with underlying hepatitis B virus infection and hepatoid adenocarcinoma with liver metastasis mimicking hepatocellular carcinoma. CASE PRESENTATION: We present the case of a 56-year-old Chinese female with underlying hepatitis B virus infection, who was found to have multiple hepatic tumors by abdominal ultrasound and an elevated level of serum alpha-fetoprotein. Hepatocellular carcinoma was considered based on the image findings, the elevated level of serum alpha-fetoprotein. and underlying hepatitis B virus infection. Moreover, the subsequent endoscopy revealed gastric tumor. However, the tumor histology of the stomach and liver revealed glandular adenocarcinoma with hepatoid foci. The final diagnosis is hepatoid adenocarcinoma of the stomach with liver metastasis. CONCLUSION: Hepatoid adenocarcinoma is an aggressive tumor with liver metastasis being the first clinical manifestation of the neoplasm. Hepatoid adenocarcinoma of the stomach with liver metastasis should be considered in older patients with elevated serum alpha-fetoprotein and multiple hepatic tumors with underlying chronic liver disease. An upper gastrointestinal endoscopy should be performed to exclude the possibility of hepatoid adenocarcinoma originating from the stomach to avoid potential misdiagnosis and inappropriate therapy.