Placental mesenchymal dysplasia associated with fetal aneuploidy

Objectives: To describe three cases of placental mesenchymal dysplasia (PMD) associated with abnormal karyotype and review the cases reported in the literature.

Methods: The cases were retrieved from the files of three different institutions. A search of the English language literature was performed using Medline database.

Results: Placental abnormalities suggestive of molar changes were seen on the prenatal ultrasound scans. Histologically, the cases had large, hydropic stem villi with myxomatous stroma, cistern formation and 'chorangiomatoid' changes. The placental and fetal karyotypes identified were trisomy 13 (47,XX,t(1:13)(q32;q32)+ 13); Klinefelter syndrome (47,XXY) and triploidy (69,XXX). Including these 3 cases, of 66 reported cases, 51 (78%) were female and 14 (22%) male (ratio 3.6:1); the karyotype was normal in 32/36 (89%) and abnormal in 4/36 (11%); Beckwith-Wiedemann syndrome was confirmed or suspected in 15/66 (23%). Excluding termination of pregnancies, intrauterine death occurred in 18/54 (33%) cases.

Conclusion: Molar ultrasonographic appearances associated with increased maternal serum alpha-fetoprotein but normal, or slightly elevated, levels of ss human Chorionic Gonadotrophin should raise the clinical suspicion of PMD. The diagnosis of this condition should not be disregarded when an abnormal fetus and/or an abnormal karyotype are demonstrated.