[A primary choriocarcinoma of the stomach with a review of 45 cases in Japan].

A case of a primary choriocarcinoma of the stomach is reported together with review of 44 cases in the Japanese literature. The patient, a 79-year-old male complaining of severe anemia, was admitted to hospital. As a result of a gastric endoscopy, a carcinoma was diagnosed and a laparotomy was performed. Because of an extensive metastasis, however, the surgery was limited to a palliative proximal gastrectomy. Pathologically, the tumor was a choriocarcinoma, and the HCG in the blood was slightly elevated. Immunohistologically, however, no HCG was detected. Although most cases reported in Japan support the theory of differentiations in gastric carcinomas, this choriocarcinoma suggests a separate type of differentiation in both the function and the morphology or a morphological mimicking.