Dedifferentiated endometrioid adenocarcinoma of the uterus: highly aggressive and poor prognostic tumor.

Dedifferentiated endometrioid adenocarcinoma (DEAC) is a recently described, rare uterine neoplasm containing both low-grade endometrioid adenocarcinoma and undifferentiated carcinoma.1 Undifferentiated carcinoma in DEAC may originate secondary to transformation or dedifferentiation of low-grade endometrioid adenocarcinoma and appears to be more aggressive than endometrial endometrioid adenocarcinoma.2 The undifferentiated component in DEAC can be misdiagnosed as the solid component of grade 3 endometrioid adenocarcinoma.3 Therefore, accurate diagnosis of this neoplasm is important in treatment and prognosis. Here we report a case of DEAC of the uterus.