[The diagnosis of uterine leiomyosarcoma and endometrial stromal sarcoma]

The diagnostic problems in uterine smooth muscle tumors and endometrial stromal tumors are reviewed and discussed with analysis of 14 selective cases collected from the affiliated hospital. Data suggested that, in the differential diagnosis of benign and malignant uterine smooth muscle tumors, it is not comprehensive to use mitotic activity as the only criterion. Nuclear atypia and some other clinico-pathological features should be considered together, and, it is important to recognize the "mitotic active" leiomyoma which runs a benign course despite a high mitotic rate. In endometrial stromal sarcoma, the growth pattern and the extent of tumor spreading seem not closely correlated with the mitotic activity, nor the atypia, and, the clinical stage was considered as a significant reference in the prognosis. Thus, it is suggested that the differentiation of endometrial stromal sarcoma into low and high malignancy according to the mitotic rate alone is not the best reliable guide in evaluating the tumor behavior. It is emphasized that the extent of spreading of the tumor should be stated in the diagnosis. Immunohistochemical study revealed that the sex cord element in endometrial stromal sarcoma and other uterine tumors expressed a myogenous rather than an epithelial phenotype.