Placental site trophoblastic tumour (PSTT) differs from choriocarcinoma in all of the following ways EXCEPT:

• A PSTT secretes human placental lactogen (hPL) more than β-hCG
• B PSTT is relatively resistant to chemotherapy
• C PSTT is treated primarily with hysterectomy
• D PSTT has a higher response rate to EMA-CO than choriocarcinoma ✓

Explanation

PSTT arises from intermediate trophoblast (implantation site), primarily secretes hPL with only mildly elevated β-hCG, is relatively chemoresistant, and is treated primarily by hysterectomy. Unlike choriocarcinoma, which has an excellent response rate (>90%) to EMA-CO, PSTT is notably resistant to EMA-CO; EP-EMA is used for chemotherapy-requiring PSTT. All other features listed (hPL secretion, chemoresistance, surgical treatment) correctly distinguish PSTT from choriocarcinoma.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.