Incidental Intraplacental Choriocarcinoma in the Setting of Intrauterine Fetal Demise.

Gestational trophoblastic neoplasia (GTN) is a rare group of pregnancy-related diseases involving the abnormal transformation of placental cells with metastatic potential. GTN includes choriocarcinomas, epithelioid trophoblastic tumors, placental site trophoblastic tumors, and invasive moles. The clinical presentation of GTN is often indolent and ultimately fatal if left untreated. Given the presentation of GTN and its low incidence, clinical care and proposed guidelines for managing GTN are limited, with a primary reliance on serum β-hCG levels for treatment and surveillance. In this case report, we describe a case of intraplacental choriocarcinoma (IC) in the setting of intrauterine fetal demise (IUFD). We share the histopathologic diagnosis, the clinical management and surveillance for residual disease, and highlight the importance of placental examination for the purposes of building out clinical practice guidelines.