Placental site trophoblastic tumour (PSTT) differs from choriocarcinoma in all of the following EXCEPT:
- A PSTT arises from intermediate trophoblast cells
- B PSTT is relatively resistant to EMA-CO chemotherapy
- C PSTT is equally sensitive to single-agent methotrexate as low-risk GTD ✓
- D PSTT produces mainly hPL (human placental lactogen) rather than hCG
Correct answer: C. PSTT is equally sensitive to single-agent methotrexate as low-risk GTD
Explanation
PSTT is NOT equally sensitive to standard GTN chemotherapy including single-agent methotrexate or EMA-CO — it is characteristically chemo-resistant relative to other trophoblastic tumours. Hysterectomy is the treatment of choice for localised PSTT. PSTT does arise from intermediate trophoblast (true), is relatively resistant to EMA-CO (true), and produces mainly hPL with low hCG (true). Hence the statement that it is 'equally sensitive' is false.
Reference: Williams Obstetrics, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.