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| Values are valid only on day of printing | |
| Web: | mayocliniclabs.com |
|---|---|
| Email: | mcl@mayo.edu |
| Telephone: | 800-533-1710 |
| International: | +1 855-379-3115 |
| Values are valid only on day of printing | |
A 31-year-old G1P0 woman with oligohydramnios underwent emergent caesarean section at 36 weeks gestation for non-reassuring fetal heart tones. She delivered a liveborn, pale-appearing female infant. Gross examination of the placenta demonstrated multiple tan-yellow infarcts, including one with focal hemorrhage. Histologic sections of the parenchymal infarcts are represented in Figures 1 and 2.
The correct answer is ...
It can present as an incidental microscopic finding during placental examination.
The diagnosis is intraplacental choriocarcinoma. Choriocarcinoma is a biphasic malignant tumor composed of mononuclear trophoblast (i.e., cytotrophoblast, intermediate trophoblast) and multinucleated syncytiotrophoblast and can be gestational or non-gestational in origin. Gestational choriocarcinoma is frequently preceded by a complete hydatidiform mole, exhibiting an androgenetic (paternal only) genome, and is characterized pathologically by invasive sheets of biphasic trophoblast with marked cytologic atypia, increased mitotic activity, and large regions of hemorrhage and necrosis. The finding of chorionic villi is generally considered incompatible with a diagnosis of choriocarcinoma.
Intraplacental choriocarcinoma is a distinct type of gestational choriocarcinoma typically discovered in a third trimester placenta of a nonmolar (biparental diploid genome) gestation and contains chorionic villi displaying multiple layers of biphasic pleomorphic trophoblast extending into the intervillous space associated with villous infarcts and necrosis (Figures 1 and 2). Intraplacental choriocarcinoma is rare and likely underrecognized. It can present clinically as metastatic disease in the mother, fetomaternal hemorrhage, or stillbirth, or it may be detected as an incidental finding during placental examination. Grossly, intraplacental choriocarcinoma ranges from an identifiable mass lesion to resembling infarcts, thrombi, or fibrin deposition to appearing normal, and the diagnosis is determined microscopically.
Intraplacental choriocarcinoma confined to the placenta is associated with an excellent prognosis, and management by surveillance serum hCG levels has been proposed. Maternal metastatic disease is detected in approximately 50% of cases and has a relatively good prognosis following chemotherapy. Fetal metastasis occurs rarely and is associated with a poor outcome. It has been reported that approximately 60% of pregnancies complicated by intraplacental choriocarcinoma result in a liveborn infant with low neonatal mortality. Management by surveillance serum hCG levels has been proposed. Maternal metastatic disease is detected in approximately 50% of cases and has a relatively good prognosis following chemotherapy. Fetal metastasis occurs rarely and is associated with a poor outcome. It has been reported that approximately 60% of pregnancies complicated by intraplacental choriocarcinoma result in a liveborn infant with low neonatal mortality.
Luisa Ricaurte Archila, M.D.
Resident, Anatomic & Clinical Pathology
Mayo Clinic
@LuisaRicaurteMD
Amy Swanson, M.D.
Senior Associate Consultant, Anatomic Pathology
Mayo Clinic
Assistant Professor of Laboratory Medicine and Pathology
Mayo Clinic College of Medicine and Science
