Placental Site Trophoblastic Tumor

Comments:
Placental site trophoblastic tumor (PSTT) is a rare testicular trophoblastic tumor that resembles its counterpart in the uterus. Pure testicular PSTT is rare. Most cases are seen as a component of mixed germ cell tumor.

PSTT lacks the biphasic pattern of choriocarcinoma and consists of nodules of intermediate trophoblasts in a fibrous background. This image is from a PSTT involving the uterus. The tumor cells are seen infiltrating the myometrium.