Which histopathological finding in the placental bed is considered the characteristic lesion of pre-eclampsia?

• A Physiological conversion of spiral arteries extending into the myometrial segments
• B Hyperplastic arteriolosclerosis of decidual vessels
• C Acute atherosis with fibrinoid necrosis of spiral arterioles ✓
• D Villous oedema with proliferation of cytotrophoblast

Explanation

In normal pregnancy, extravillous trophoblast invades and converts spiral arteries into low-resistance vessels. In pre-eclampsia this conversion is shallow and incomplete, and the retained muscularised arterioles develop acute atherosis, characterised by fibrinoid necrosis, lipid-laden macrophages, and perivascular lymphocytic infiltration. This lesion produces high-resistance uteroplacental flow and underlies fetal growth restriction. Physiological conversion into myometrial segments is the normal finding, hyperplastic arteriolosclerosis is a lesion of malignant hypertension, and villous changes are secondary rather than diagnostic.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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