La dysplasie mésenchymateuse du placenta

Vesicules or placental lakes in ultrasonography, determining the correct etiology

The prenatal examination of the placenta is often an afterthought to that of the fetus in ultrasonography. Not giving the placenta its due may however result in potentially serious placental pathologies remaining undiscovered, notably in the presence of anechoic zones. These latter have earned numerous names, including "placental lakes", "placental venous lakes", "placental lacunae" or "placental caverns" among others, but they have received little attention in the literature. We thus feel that it is essential to review the various pathologies that placental lakes may signal, since any one of them may greatly affect patient management. The difficulty resides in the diversity of these pathologies, sometimes oncological, other times fetal, and in the potential need for multidisciplinary surgery. Some of these causes of placental lakes may result in maternal or fetal complications and/or necessitate increased and casespecific surveillance. The diagnosis and treatment of such cases requires close collaboration between sonographers, obstetricians, geneticists and pathologists. The work we present here focuses on the different etiologies to consider in the presence of a lacunar placenta and the necessary diagnostic measures. Our objective is to propose a diagnostic flowchart to aid clinicians in this dense differential diagnosis.

Placental mesenchymal dysplasia: An underdiagnosed placental pathology with various clinical outcomes

BACKGROUND

Placental mesenchymal dysplasia (PMD) is a rare vascular and connective placental anomaly, which is often associated with severe fetal and/or maternal complications. The diversity of presentation of PMD challenges diagnosis and effective pregnancy management.

OBJECTIVE

We aimed to review cases presenting at 7 tertiary centers worldwide over the last decade and to study the occurrence of obstetric and neonatal complications.

STUDY DESIGN

Pathology databases from 7 tertiary hospitals were screened for cases of PMD (between 2007-2017). Pregnancy history, outcomes and ultrasound images were then reviewed for each case.

RESULTS

Twenty-two cases of PMD were identified. Mean gestational age at diagnosis was 23 weeks (16-39 weeks). Prenatal biochemical screening was abnormal in 8 cases (36%). Of the 12 cases that underwent invasive genetic testing, 4 were abnormal. Six patients (27%) developed maternal complications (preeclampsia/gestational hypertension). Fetal growth restriction was identified in 11 cases (50%) and fetal death in 4 (18%). Four (18%) pregnancies were terminated, 9/14 (64%) delivered preterm and only three (14%) progressed normally. Fourteen babies were born alive; 5 (35%) died in the first sixty-one days after birth, 5 (35%) had transient thrombopenia and 1 (7%) had developmental delay at last follow-up. Our series identified four potential new associations with PMD: placental triploidy mosaicism, CHARGE syndrome, fetal pleuropulmonary blastoma and fetal skeletal dysplasia.

CONCLUSIONS

PMD was substantially under-diagnosed before delivery in this cohort. Sonographers, fetal medicine specialists, obstetricians and pathologists should all suspect PMD in cases of an enlarged placenta and should look for fetal abnormalities. Diagnostic genetic testing should be discussed to exclude partial molar pregnancy. Close pregnancy follow-up is indicated due to the high risk of associated fetal or maternal adverse outcomes.

[Placental mesenchymal dysplasia: consequences for the newborn]

CASE REPORT

We report the case of a newborn presenting with anemia, thrombopenia, intrauterine growth restriction (IUGR), and hepatic hemangioma revealing placental mesenchymal dysplasia.

CONCLUSION

This rare disease is not always diagnosed during pregnancy. Placental chorioangioma is responsible (in the absence of lethal complications in utero) for IUGR, anemia, neonatal thrombopenia, and hepatic or cutaneous hemangiomas. The early search for hemangiomas with ultrasound scanning could be useful to predict cardiac failure by left-to-right shunt.