Placental site trophoblastic tumor (PSTT) differs from choriocarcinoma in which important clinical characteristic?
- A PSTT has a much higher β-hCG level and is highly chemosensitive
- B PSTT is characterised by relatively low β-hCG (often < 1000 IU/L) and is resistant to EMA-CO chemotherapy ✓
- C PSTT arises exclusively from complete hydatidiform moles
- D PSTT requires brachytherapy rather than surgery
Correct answer: B. PSTT is characterised by relatively low β-hCG (often < 1000 IU/L) and is resistant to EMA-CO chemotherapy
Explanation
Placental site trophoblastic tumor (PSTT) is derived from intermediate trophoblast cells and secretes predominantly human placental lactogen (hPL) with relatively low β-hCG (usually < 1000 IU/L), in contrast to choriocarcinoma's massively elevated β-hCG. PSTT is notoriously resistant to standard EMA-CO chemotherapy and is treated primarily by hysterectomy. EMA-EP (etoposide, methotrexate, actinomycin-D, etoposide, cisplatin) has activity in metastatic PSTT.
Reference: Shaw's Textbook of Gynaecology, 17th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.