Choriocarcinoma in Situ in a Partial Hydatidiform Mole A: Case Report

Choriocarcinoma most frequently arises in a complete hydatidiform mole. Less common are cases following a normal pregnancy or a nonmolar abortion. Its occurrence after a partial hydatidiform mole is extremely rare.

Here we report a choriocarcinoma in situ diagnosed after dilation and curettage for a first tri- mester partial hydatidiform mole. The diagnosis was con- firmed by immunohistochemistry, fluorescent in situ hybridization, and microsatellite instability genotyping of the products of conception and blood of the mother and father. We demonstrated a diandric triploidy. At the time of diagnosis CT scan showed lung metastasis. The pa- tient was classified as high-risk gestational trophoblas- tic neoplasia and treated with high-dose methotrexate- etoposide.

This is the first reported case of a cho- riocarcinoma arising in a first trimester partial mol.