A 28-year-old primigravida at 28 weeks is diagnosed with pre-eclampsia. The pathologist examines the placental bed biopsy. Which histopathological finding is CHARACTERISTICALLY ABSENT in pre-eclampsia compared to a normal pregnancy?
- A Fibrinoid necrosis of spiral arteries
- B Acute atherosis of decidual vessels
- C Physiologic conversion of spiral arteries by endovascular trophoblast ✓
- D Intervillous thrombus formation
Correct answer: C. Physiologic conversion of spiral arteries by endovascular trophoblast
Explanation
In normal pregnancy, endovascular trophoblast invades the decidual and myometrial segments of spiral arteries, replacing the muscular wall to create low-resistance, high-flow vessels. In pre-eclampsia, this physiologic conversion is shallow and incomplete, restricting placental perfusion. Acute atherosis and fibrinoid necrosis are actually PRESENT in pre-eclampsia as secondary changes, not absent. The absent feature is the normal physiologic conversion.
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.