A Case Report of Malignant Mullerian Mixed Tumor of the Uterus

We experienced a case of malignant Mullerian mixed tumor of the uterus of a 58-year-old female. We performed an immunohistochemical study in order to analyze the expres-sion of various antigens in different elements of this tumor. Keratin, carcinoembryonic antigen (CEA), and epithelial membrane antigen (EMA) showed strong positive results in epithelial component, while EMA also showed positive results in some areas of sarcomatous elements. On the other hand, vimentin and S-100 gave strong positive result in non-epithelial component, but also was positive to some extent in epithelial component in this tumor. Immuno-histochemical method was useful to differentiate the different components of this tumor. However, EMA, Vimentin and S-100 showed some unusual results. This discrepancy may indicate a change in the nature of tumor cells due to `microenvironmental ' factors such as hormones and vita-mins. Therefore, careful evaluation is necessary to interpret the immunohistochemical results in surgical pathology