Placental mesenchymal dysplasia presenting as a twin gestation with complete molar pregnancy.

BACKGROUND

Placental mesenchymal dysplasia is a rare abnormality characterized by placentomegaly, grapelike cystic vesicles, and villous hyperplasia. The clinical and ultrasonographic presentation may mimic molar pregnancy, provoking incorrect diagnoses and unnecessary therapeutic interventions.

CASE: A 36-year-old nulliparous woman presented for prenatal ultrasonography that indicated the presence of one gestational sac containing both fetus and cystic mass, concerning for partial molar pregnancy. Amniocentesis returned a 46,XX karyotype, suggesting a twin gestation with complete mole. The patient was monitored closely and, because of fetal growth restriction, was induced successfully at term and delivered a healthy newborn. Histopathologic findings of the placenta were consistent with placental mesenchymal dysplasia.

CONCLUSION

Although placental mesenchymal dysplasia is often confused with molar pregnancy, it is important to consider both in a differential to avoid inappropriate treatments.