Primary adenocarcinoma with choriocarcinomatous differentiation of the sigmoid colon misdiagnosed choriocarcinoma of the uterus: case report and review of the literature

Choriocarcinoma is a highly malignant tumor of trophoblastic cells that most often arises in the placenta, but may also develop in extragonadal tissues. Primary extragonadal choriocarcinoma, especially in the gastrointestinal tract, is extremely rare and is associated with poor prognosis. This report describes a 44-year-old Korean woman who was initially diagnosed incorrectly with choriocarcinoma of the uterus, but was ultimately diagnosed with primary adenocarcinoma accompanied by focal choriocarcinomatous differentiation in the sigmoid colon and secondary degeneration of submucosal myoma. Her progression was rapid and because of her poor general condition, she received only a single cycle of cisplatin chemotherapy. She died of multioigan failure due to multiple metastases two months after the initial diagnosis.