A 26-year-old hemodynamically stable woman with a documented intrauterine pregnancy of 7 weeks requests medical management for termination. On day 2 after misoprostol, she develops heavy bleeding and passes tissue. Histopathology reveals intermediate trophoblast infiltration of the myometrium without villi, and serum hCG is modestly elevated at 600 mIU/mL. What is the most likely diagnosis?
- A Invasive mole
- B Choriocarcinoma
- C Placental site trophoblastic tumor ✓
- D Exaggerated placental site reaction
Correct answer: C. Placental site trophoblastic tumor
Explanation
Placental site trophoblastic tumor (PSTT) is characterized by infiltration of the myometrium by intermediate trophoblasts WITHOUT villi, with modestly elevated hCG (since it is primarily human placental lactogen, hPL, driven). Invasive mole contains villi. Choriocarcinoma has both cytotrophoblast and syncytiotrophoblast without villi but with hemorrhage and necrosis, and typically much higher hCG.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.