Primary gastric choriocarcinoma: immunohistochemistry, postmortem documentation, and hormonal effects in a postmenopausal female.

A rare tumor, primary choriocarcinoma of the stomach, occurred in a post menopausal female. The diagnosis was confirmed by autopsy and by immunohistochemical demonstration of HCG in trophoblastic tumor cells. Theories concerning development of this neoplasm are briefly discussed. In addition, this postmenopausal case uniquely permitted examination of the hormonal effects of the tumor on target tissues without the clouding issue of normal menstrual hormones. It appears that the observed estrogen- and progesterone-related tissue responses were not mediated through the ovary; instead, direct tumor production of these hormones is implicated.