Gastric cancer with choriocarcinoma and yolk sac tumor components: case report.

Choriocarcinoma- and yolk sac tumor-like differentiation have rarely been reported in gastric cancers. We report a case of gastric adenocarcinoma, concurrently possessing choriocarcinoma and yolk sac tumor components, of a 74-year-old man. A hemorrhagic, 11 × 8 × 3 cm, tumor with ulceration was located in the body and pre-pylorus of the stomach. Histological examination of the resected specimens demonstrated intermingled proliferation of three different components, namely, adenocarcinoma, choriocarcinoma and yolk sac tumor, which were immunoreactive for carcinoembryonic antigen (CEA), beta-subunit of human chorionic gonadotropin (HCG) and alpha-fetoprotein (AFP), respectively. Gastric cancers with germ cell tumor components are uncommon and this is the second reported case of gastric cancer with choriocarcinoma and yolk sac tumor components.