Gestational intraplacental choriocarcinoma in a term pregnancy and delivery: a case report and review of the literature

Introduction: Choriocarcinoma is a rare but highly malignant trophoblastic neoplasm. Cases of its coexistence with or after a “normal” pregnancy are extremely rare. Intraplacental choriocarcinoma is rare, and usually results in maternal metastasis at the time of diagnosis. Case presentation: We present the case of a 29 year-old gravida 1 para 0 Chinese woman who delivered a viable 3,140 g female infant at 38 weeks’ gestation. Because of the patient’s history of gestational diabetes mellitus and hepatitis B positive status, the placenta examined pathologically, and placental choriocarcinoma was diagnosed. The patient denied any previous pregnancies. Her serum beta human chorionic gonadotropin was 3573.7 mIU/ml 4 days after cesareansection, and dropped to less than 5 mIU/ml six weeks post-partum. There were no signs of dissemination; therefore, the patient received one course of chemotherapy. To date, both mother and baby are well. Conclusion: We postulate that the prevalence of intraplacental choriocarcinoma is notably higher than previously reported and remains undetected because it is not routine practice to send placentas for pathological evaluation after a normal spontaneous delivery. This case clearly illustrates the importance of detailed examination of the placenta and its full significance in diagnosing choriocarcinoma in the mother. To our knowledge, this is the first report of a case of intraplacental choriocarcinoma without any previous forms of pregnancy. Our case provides evidence that the choriocarcinoma may arise from an normal placenta.