title: Partial molar transformation of the placenta of presumably monozygotic twins.
abstract: A pregnancy with one normal female fetus and a placenta that was divided into halves, one normal the other molar, is described. Genetic analysis shows the molar component to be hyperdiploid/tetraploid but having an identical DNA composition as the normal twin. Because there was no trophoblastic proliferation and the hyperdiploid cells were confined to the villous stroma, and because the molar component was still being perfused by diploid vessels from the normal twin, we believe the mole is derived from polyploidization of the mesenchymal epiblast in a monozygotic twin pregnancy.
authors.affiliation: Department of Pathology, University of California San Diego, University Medical Center, 200 West Arbor Drive, San Diego, CA 92103-8321, USA.
authors.forename: K
authors.initials: K
authors.lastname: Benirschke
authors.forename: J C
authors.initials: JC
authors.lastname: Spinosa
authors.forename: M J
authors.initials: MJ
authors.lastname: McGinniss
authors.forename: A
authors.initials: A
authors.lastname: Marchevsky
authors.forename: J
authors.initials: J
authors.lastname: Sanchez
mesh_terms: D000328:Adult; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D006828:Hydatidiform Mole / Q000473:pathology*; D010920:Placenta / Q000473:pathology*; D011247:Pregnancy; D011252:Pregnancy Complications, Neoplastic / Q000473:pathology; D014430:Twins, Monozygotic; D014594:Uterine Neoplasms / Q000473:pathology*