Dimorphic trophoblastic cells with necrosis & hemorrhage
Tissue invasion present, No chorionic villi

Dimorphic trophoblastic cells with hemorrhage, tissue invasion

Worm-like syncytiotrophoblasts and mononucleate trophoblasts with cellular atypia and mitoses

Hemorrhage
Necrosis
Syncytio- trophoblast
Serum hCG
Preceded by a pregnancy

Clinical features:

Persistent GTD after hydatidiform mole, months after last known pregnancy

High serum hCG (>10,000 mIU/ml)

Good response to chemotherapy (MTX based)

Dimorphic (mononucleate trophoblast + syncytiotrophoblast) population of the trophoblast

Pleomorphic tumor cells with frequent mitoses

No chorionic villi

Central hemorrhage and necrosis (viable tumor cells in the surrounding rim of the tumor)

Tissue invasion (essential for the diagnosis)