PMC7102899_01
Ultrasonographic findings of the placenta. (
A
) Markedly thickened placenta with multiple cystic structures. (
B
) No blood flow was observed in the cystic lesion. Macroscopic findings of the placenta. (
C, D
) Cystic structures similar to molar pregnancy observed in places on the maternal side of the placenta.
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On ultrasonography, the placenta was markedly thickened ( Fig. 1A ) and multiple cystic structures without internal blood flow were observed ( Fig. 1B ). Cystic structures similar to a molar pregnancy were observed in places on the maternal side of the placenta ( Fig. 1C, D ).
Microscopic findings of the placenta. (
A, B
) Enlarged stem villi with cistern (
asterisk
) or edematous loose myxoid stroma (
arrowheads
) were focally present, surrounded by normal-appearing villi with gestational age-appropriate maturation. (
C, D
) Absence of trophoblastic hyperplasia or inclusions, suggestive of molar pregnancy (
arrows
) Original magnification A: x12.5, B-D: x40. A-D: Hematoxylin & eosin stain.
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 Microscopic findings of the placenta revealed focal enlarged stem villi with cistern and edematous loose myxoid stroma, surrounded by apparently normal villi with maturation consistent with the patient's gestational age ( Fig. 2A, B ). Trophoblastic hyperplasia or inclusions, suggestive of molar pregnancy, were absent ( Fig. 2C, D ).
Histological findings of decidual vessels. (
A-D
) Vasculopathy characterized by fibrinoid necrosis and infiltration of foamy macrophages (
arrows
) in the vascular wall Original magnification A, B: x100, A, B: Hematoxylin & eosin stain.
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Histological findings of decidual vessels revealed vasculopathy characterized by fibrinoid necrosis and infiltration of foamy macrophages in the vascular wall, either of which is characteristic of gestational hypertension and fetal growth restriction ( Fig. 3 ). 
(
A
) Formation of fresh thrombus in a chorionic vessel lumen (
arrows
). (
B
) Marked luminal stenosis with organizing intimal sclerosis in some of the chorionic vessels (
asterisk
) Original magnification A, B: x100, C, D: x200.
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Immunohistochemical staining of sFlt in trophoblasts of PMD (
A, B
) and control (
C, D
). Higher expression of sFlt was identified in the syncytiotrophoblast of enlarged villi in PMD (
arrows
), whereas its expression was weak in the control case, wherein the pregnancy was terminated at 20 weeks gestation due to uterine rupture. sFlt, soluble fms-like tyrosine-kinase-1; PMD, placental mesenchymal dysplasia.
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Immunohistochemical staining of trophoblasts of PMD showed a high expression of sFlt-1 localized in the syncytiotrophoblast of the enlarged villi in PMD ( Fig. 5A ). However, its expression was weak in a control case terminated at 20 weeks of gestational age due to uterine rupture ( Fig. 5B ).