Primary gastric choriocarcinoma. An immunohistological study

Two cases of extragenital choriocarcinoma arising in association with gastric adenocarcinoma are described. Using immunohistochemical methods, cells containing human chorionic gonadotropin, beta-subunit (hCG-beta) were localized exclusively to the choriocarcinomatous portion of the tumor. One patient whose tumor appeared to confined to the stomach at the time of surgery, had elevated serum hCG-beta postoperatively. Metastases became evident subsequently.