Intraplacental Gestational Neoplasms: A Review of Clinically Relevant Diagnostically Challenging Lesions.

* Context.--Case studies reporting intraplacental choriocarcinoma (IPC) and intraplacental "chorangiocarcinoma" have recently increased, with IPC also represented in molecular analyses of gestational trophoblastic neoplasms. Objective.--To provide an overview of 2 intraplacental neoplastic lesions that can have a significant impact on both mother and fetus/infant, focusing on diagnostic characteristics, and ancillary and molecular tools that support diagnosis, determine prognosis, and further elucidate the nature of these lesions. Data Sources.--Data were compiled from a PubMed literature review that included diagnostic and additional keywords within the scope of study for gestational choriocarcinoma in general. Illustrative cases were retrieved from the pathology archives at Michigan Medicine, including the consultation files of the author. Conclusions.--Intraplacental gestational tumors exist along the spectrum of benign (chorangioma) to aggressive malignant (choriocarcinoma) neoplasms with a high potential for metastasis. Although most gestational choriocarcinomas follow complete hydatidiform mole, 20% to 25% occur in association with normal intrauterine gestations, including rare cases in which they are detected within the placenta (IPC). IPCs range from asymptomatic to widely metastatic, with metastases possible even when only microscopic IPCs are present. A second, even less common lesion, variably called "chorangiocarcinoma" and chorangioma with atypical trophoblast proliferation, is also reviewed. The incidence of these lesions is likely to be underestimated. Heightened suspicion and more liberal placental sampling, particularly when specific clinical features are present, may result in higher detection. Enhanced detection to provide the earliest intervention for both mother and infant may improve prognosis, particularly for asymptomatic disease that may later present with metastasis. [ABSTRACT FROM AUTHOR]