[A case of a male gastric choriocarcinoma with massive mesenteric tumor and review of the literature on male choriocarcinoma].

A 32-year-old man was admitted to our hospital, complaining of an abdominal mass. An operation disclosed a large tumor, the size of a child's head, in the mesenterium of the transverse colon, with a multiple liver metastasis. A tumor resection was performed and, histologically, the tumor was diagnosed as being a choriocarcinoma. Gynecomastia was not observed. The patient died 2 months after this operation in spite of chemotherapy. An autopsy disclosed metastatic choriocarcinomas in the lungs, the liver, the peritoneum, the stomach, the adrenal glands and in the lymph nodes. The testis was found to be normal by a serial histological examination. Primary advanced adenocarcinoma, which is histologically similar to a choriocarcinoma, was found in the stomach. This case was finally diagnosed as being a gastric adenocarcinoma which showed choriocarcinomatous differentiation at various metastatic sites.