Epithelioid trophoblastic tumor (ETT) is distinguished from placental site trophoblastic tumor (PSTT) by which histological and clinical feature?

• A ETT arises from syncytiotrophoblast while PSTT arises from cytotrophoblast
• B ETT produces predominantly β-hCG while PSTT produces hPL
• C ETT arises from chorionic-type intermediate trophoblast (membranes/chorion laeve), PSTT from implantation-site intermediate trophoblast ✓
• D ETT is associated with complete mole while PSTT follows ectopic pregnancy

Explanation

Both PSTT and ETT are non-gestational trophoblastic tumors derived from intermediate trophoblast but from different anatomical origins: PSTT arises from implantation-site intermediate trophoblast (invades myometrium), while ETT arises from chorionic-type intermediate trophoblast (membranes, chorion laeve). ETT may occur in the cervix as well as the uterus. Both produce low levels of β-hCG and hPL, but ETT stains more positively for p63 (a squamous epithelial marker) and can mimic squamous cell carcinoma histologically. Both are relatively resistant to EMA-CO.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.