Choriocarcinoma of Breast
Upper half shows a hemorrhagic area of the tumor. The lower half is composed of large syncytiotrophoblastic cells with irregular nuclei, coarse chromatin, and prominent nucleoli. A few benign entrapped ducts are seen near the center. Isolated tumor cells with immunoreactivity for beta-hCG can be seen in between 5% to 20% of ordinary infiltrating ductal carcinomas. This finding has no prognostic significance.