differentiation: a case report and review of the literature

Objective An endometrioid adenocarcinoma (EAC) with true trophoblastic differentiation is a rare event with a highly aggressive clinical course.Case We report an endometrioid adenocarcinoma of the endometrium in which there was a morphologically conventional-appearing EAC component admixed with multinucleated giant cells and large pleomorphic tumor cells that resembled a choriocarcinoma without an elevated serum level of human chorionic gonadotropin (hCG) in a 42-year-old unmarried woman with a history of abnormal uterine bleeding. A total abdominal hysterectomy, bilateral salpingo-oophorectomy, and pelvic lymph node dissection were performed. Histopathologic study of the specimen showed endometrioid adenocarcinoma extended to the deep myometrium with a focus of hemorrhagic and necrotic tumor composed of multinucleated giant cells, large pleomorphic tumor cells, suggesting choriocarcinomatous differentiation (CD). Immunohistochemical studies demonstrated intense reactivity of tumor cells for human chorionic gonadotropin (hCG) confirming the diagnosis. A complete clinical workup ruled out metastatic spread to the brain, lungs, skeleton, or abdomen. The patient was alive with no evidence of disease 6 months later.Conclusion Although endometrioid adenocarcinoma with choriocarcinomatous differentiation is known to behave in a more aggressive course, this disease may have a good prognosis with a clinically indolent course when it is small, and without elevated serum hCG levels