Chorangiocarcinoma of the placenta: a case report and clinical review.

OBJECTIVE

We describe a case of chorangiocarcinoma, a complex lesion consisting of a trophoblastic proliferation within a chorangioma, presenting in a term placenta.

MATERIALS AND

METHODS

The lesion was diagnosed by ultrasound at a second trimester check-up after amniocentesis, performed because of increased combined risk at first trimester screening for trisomy 21. After uncomplicated vaginal delivery, a healthy child was born and the placenta was expelled spontaneously.

RESULTS

Gross examination of the placenta showed a well-demarcated mass, bulging paracentrally from the fetal surface. Histology revealed a trophoblastic proliferation inside a chorangioma, consisting of multiple nodules with characters of focal multinucleation and pleomorphic cell nuclei, extensive central necrosis and high mitotic activity. Immunohistochemical staining showed strong intensity for hCG; Ki-67 (MIB-1) demonstrated a high proliferation index. Histopathological and immunohistochemical profile was compatible with a malignant trophoblastic proliferation.

CONCLUSIONS

This is only the fifth reported case of so-called "chorangiocarcinoma" of the placenta (Table 1). However, histopathologically only one reported case was identical to ours. A proliferation of atypical trophoblast was observed inside a chorangioma, which formed as it were a shield around the trophoblast. No extravascular stromal invasion was present. Follow-up revealed no metastases, either in the mother or the child, up to 3 months after birth.