Abstract
A 64-years old man was admitted to our hospital complaining of appetite loss. His blood test showed anemia. Endoscopic examination revealed a large protruding lesion showing submucosal tumor-like appearance within a deep ulcer. Abdominal enhanced computed tomography showed a tumor with extragastric growth, measuring 10 cm, with necrosis, and showed multiple metastases to the liver. The serum alpha fetoprotein （AFP） level was 31.2 ng/ml. Because the biopsy specimen revealed poorly differentiated adenocarcinoma, the chemotherapy （S1/CDDP） was started. However the treatment was ineffective, the patient died after 47 days. The autopsy findings of the gastric tumor revealed hepatoid adenocarcinoma and tubular adenocarcinoma, and the diagnosis of hepatoid adenocarcinoma was established. Immunostaining for tubular adenocarcinoma lesion was positive for AFP, but for hepatoid adenocarcinoma lesion was negative. Hepatoid adenocarcinoma accounts for 0.2％ of all gastric tumors. In the Japanese literature, 88 cases including our case have been reported, 81％ cases were advanced type and 2％ cases showed submucosal tumor-like appearance, 44％ cases were with liver metastasis. The serum AFP level was more than 1,000 ng/ml in 55％ cases, but in only 10％ cases was less than 50 ng/ml. Hepatoid adenocarcinoma lesion is usually mixed with tubular adenocarcinoma lesion and rarely found in mucosal layer. Therefore only 11％ cases were diagnosed by biopsy specimens.
