Choriocarcinoma coexistent with intrauterine pregnancy: two additional cases and a review of the literature.

Choriocarcinoma coexistent with normal intrauterine pregnancy is rare and poses questions about its origin. Although the development from trophoblastic remnants of previous pregnancies can not be excluded in some cases, the findings of incidental macro- and microscopic foci of choriocarcinoma in apparently normal placentas show the possible transformation of normal trophoblast into choriocarcinoma during an otherwise normal pregnancy. The diagnosis and management of choriocarcinoma coexistent with intrauterine pregnancy have changed dramatically over the decades but the survival rates are still unsatisfactory. In this review, we summarize some of the most common features of this disease.