[Trophoblastic tumor at the site of the placenta].

The author describes the histological structure of a rare placental site trophoblastic tumor. In differential diagnosis it is necessary to take into account hydatidiform mole and chorionepithelioma. In differentiating with hydatidiform mole lack of placental villi is characteristic while with choriocarcinoma the presence of connective stroma in PSTT is helpful.