Placental site trophoblastic tumor

Placental site trophoblastic tumor (PSTT) is the rarest disease of the gestational trophoblast. Our two cases will be interesting not only because of the rarity of the disease, but because both were recognized before operation. Since the tumor cells are lined up tightly side by side, this disease must be distinguished primarily from tumors of epithelial origin. The authors highlight that the diagnosis should rely on intense hPL-positivity as well as the ultrastructural image of the tumor. In histologically equivocal cases, the determination of hPL, hCG, and MIB-1 immunologic markers can be recommended as routinely performed morphological examinations. Serum hCG monitoring is recommended to follow the evolution of the tumor.