Gastric carcinoma with predominant choriocarcinomatous component

We describe a rare case of gastric carcinoma with choriocarcinomatous differentiation. A 64-year-old Japanese man presented with an abdominal mass and was admitted to our hospital. Barium meal and endoscopic examinations disclosed a Borrmann type 2 tumor on the anterior wall of the gastric body. A subtotal gastrectomy was performed. Histopathological and immunohistochemical examinations demonstrated mostly choriocarcinomatous differentiation of the tumor, in addition to tubular adenocarcinoma. The serum human chorionic gonadotropin (hCG) level, measured after a histopathological diagnosis was made postoperatively, was 1200 IU/ml (normal range, <1.0 IU/ml). Despite resection of the tumor and chemotherapy with a curative intent, the patient died of liver metastasis 6 months after surgery.