Choriocarcinoma of Breast
Multinucleated syncytiotrophoblastic cells with highly pleomorphic nuclei and coarse chromatin are associated with clusters of smaller cytotrophoblastic cells with round vesicular nuclei. Metaplastic breast carcinomas with choriocarcinomatous component usually show areas of invasive ductal carcinoma, DCIS, or other non-choriocarcinomatous metaplastic elements. It is important to exclude metastatic choriocarcinoma to the breast. Always rule out current or recent pregnancy and enquire about history of hydatidiform mole or previous choriocarcinoma.