Decidual granulomatous reaction in a placenta from a preeclamptic pregnancy: a case report and review of the literature

We report a case of decidual perivascular non-necrotizing granulomas in a placenta from a pregnancy complicated by severe preeclampsia with no evidence of infection. The mother was a 20-year-old primigravida with severe preeclampsia diagnosed in the third trimester with subsequent delivery of a healthy baby boy at 37 weeks 5 days gestation. Pathologic examination of the placenta showed scattered non-necrotizing granulomas in decidua, often adjacent to remodeled decidual arteries without fibrinoid necrosis. These were well-formed, non-necrotizing granulomas with scant lymphoid cuffs. Polarization microscopy did not show foreign material. There were no histopathologic or clinical findings suggestive of maternal-fetal infection or systemic vasculitis at the time of delivery, and the mother had no other reported conditions associated with granulomatous inflammation. Our case demonstrates that granulomatous reaction may be seen in the placenta from a pregnancy complicated by severe preeclampsia, although work-up for infection may be indicated.