Choriocarcinoma in a term placenta with maternal metastases.

Choriocarcinoma of the nonmolar placenta is presumptively a rare entity and is usually associated with widespread maternal metastases at the time of diagnosis. Nonmetastatic disease goes unrecognized and undiagnosed because placental carcinoma can be limited to a few villi, and grossly evident disease is often misinterpreted as a placental infarct. The optimal treatment for patients with choriocarcinoma of the placenta is not known but aggressive combination chemotherapy is suggested for patients with metastatic disease. Historically, the prognosis for both mother and infant has been poor.