Concurrent endometrial intraepithelial carcinoma (EIC) and endometrial hyperplasia

Endometrial cancer is one of the most common gynecological neoplasms in the United States. It is divided into type I and type II carcinomas based on histological features. The mixed endometrioid (type I) and serous (type II) adenocarcinomas of endometrium were reported in previous studies. The concurrence of their precursor lesions was not studied. In current study, we present five cases with concurrent precursor lesions of endometrioid (endometrial hyperplasia) and serous adenocarcinomas (endometrial intraepithelial carcinoma and p53 signature). Due to the potential progressive clinical outcome of precursor lesions of serous adenocarcinoma, caution needs to be performed to identify endometrial intraepithelial carcinoma and p53 signature in the background of endometrial hyperplasia.