Cyclooxygenase-2 expression in malignant mesenchymal tumors and related uterine lesions

The aim of this study was to determine whether the expression of cyclooxyge nase-2 (COX-2) in uterine sarcoma cells and carcinosarcoma cells is associa ted with cell type. Nineteen sections of tissues from uterine sarcomas, car cinosarcomas, and an adenosarcoma, and endometrial stromal sarcomas, were i mmunohistochemically analyzed for the cellular expression of COX-2. Positiv e immunostaining for COX-2 was observed in 88.9% (8/9) uterine carcinosarco mas, uterine adenosarcomas but was not observed in uterine sarcomas and the endometrial stromal sarcoma (0/10). But positive immunostaining for COX-2 was observed in some sarcomatoid cells in carcinosarcoma tissue. These find ings suggest that some of the sarcoma cells in uterine carcinosarcomas rese mble epithelial malignant cells in regard to the increase in COX-2 expressi on, and support the hypothesis that some uterine carcinosarcomas are combin ation tumors. This may serve as a basis for new chemoprevention and treatme nt strategies for uterine carcinosarcomas through the inhibition of COX-2 a ctivity.