[Mixed mesodermal tumor of the uterine body]

During the 6-year period of 1976 to 1981, we studied 6 cases of mixed mesodermal tumor of the uterus. The incidence of occurrence of the tumor was 0.4% of all the gynecological inpatients, 1.4% of all the uterine malignancies, and 9.5% of the uterine body malignancies, and was higher than those reported by others. The patients were aged 49-75 years (mean 64 years), and 5 out of 6 patients were postmenopausal. Four patients had heterogeneous tumors (3 rhabdomyosarcomas and 1 chondrosarcoma). Two of the 6 patients are now living 34 and 14 months after treatment without clinical evidence of recurrence, respectively. Histologically, one of them showed only benign glandular structures as a component of epithelial elements, and the other one had no epithelial element. These findings suggest that the malignancy of the epithelial components may be one of the most important prognostic factors in the mixed mesodermal tumor of the uterus.