Mixed mesodermal tumor of the uterine body: relationship between histology and survival.

A clinico-pathological study of 20 cases of mixed mesodermal tumor of the uterine body is reported. Fifteen tumors were found after menopause. The mean age of all cases was 55.5 years. Histologically, mixed mesodermal tumors consisted of two different components; epithelial and sarcomatous patterns, in 18 cases. Mixed mesodermal tumors in four of the 18 cases had no adenocarcinomatous elements but showed a benign glandular structure. In the remaining two tumors, epithelial patterns were absent and only heterologous sarcomatous elements were found. Ten of the patients had received hysterectomy more than five years ago. Three of these patients, having no malignant but benign epithelial component, showed a relatively good prognosis. Adenocarcinomatous elements were found in six cases, and four patients with carcinomatous elements had poor prognosis. It can be stated that the prognosis of mixed mesodermal tumor chiefly depends on the malignancy of epithelial components, when comparing the prognosis of the tumors at the same clinical stage. On the other hand, sarcomatous elements are not likely to reflect the prognosis of the tumors. Mixed mesodermal tumor is monodermal in origin, namely, mesodermal origin, and might arise from the Muellerian duct or more primitive mesodermal tissue.