Placental Pathology in Beckwith-Wiedemann Syndrome According to Genotype/Epigenotype Subgroups.

OBJECTIVES

To evaluate the frequency of placental pathological lesions in Beckwith-Wiedemann syndrome (BWS), an overgrowth disorder that exhibits etiologic molecular heterogeneity and variable phenotypic expression.

MATERIALS AND

METHODS

The study included 60 BWS patients with a proven molecular diagnosis and a placental pathological examination. Placentomegaly, placental mesenchymal dysplasia (PMD), chorangioma/chorangiomatosis, and extravillous trophoblastic (EVT) cytomegaly were evaluated and their frequencies in the different molecular subgroups were compared. Immunohistochemistry and fluorescent in situ hybridization (FISH) were performed on EVT cytomegaly.

RESULTS

Placentomegaly was found in 70.9% of cases, PMD in 21.7%, chorangioma/chorangiomatosis in 23.3%, and EVT cytomegaly in 21.7%; there was no significant intergroup difference. EVT cytomegaly showed loss of p57 expression, increased Ki67 proliferating index, and polyploidy on FISH analysis.

CONCLUSIONS

There was no genotype/epigenotype-phenotype correlation concerning placental lesions in BWS. Diffuse EVT cytomegaly with polyploidy may represent a placental finding suggestive of BWS.