title: Extensive placental choriovascular infiltration by maturing myeloid cells in down syndrome-associated transient abnormal myelopoiesis.
abstract: Transient abnormal myelopoiesis (TAM), a clonal proliferation of predominantly megakaryocytic precursor cells, affects 4%-10% of newborns with Down syndrome. Approximately 20%-30% of TAM survivors are at risk of development of acute myeloid leukemia (myeloid leukemia associated with Down syndrome, ML-DS). We report unusual placental findings in a female infant with trisomy 21 born at 38 weeks of gestation. In line with previous descriptions of placental pathology in infants with TAM, abundant blast-like cells were present in the lumen of chorionic and stem villous vessels. In addition, there was multifocal extensive infiltration of the wall of chorionic vessels by maturing myeloid cells in a pattern reminiscent of TAM- or leukemia-associated systemic infiltration. The clinical significance of this unusual choriovascular involvement of the placenta in TAM is undetermined.
authors.affiliation: 1 Department of Pathology, Women and Infants Hospital, Providence, RI, USA.
authors.forename: Sanjita
authors.initials: S
authors.lastname: Ravishankar
authors.forename: Laurie
authors.initials: L
authors.lastname: Hoffman
authors.forename: Terakeith
authors.initials: T
authors.lastname: Lertsburapa
authors.forename: Jennifer
authors.initials: J
authors.lastname: Welch
authors.forename: Diana
authors.initials: D
authors.lastname: Treaba
authors.forename: Monique E
authors.initials: ME
authors.lastname: De Paepe
mesh_terms: D004314:Down Syndrome / Q000473:pathology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007955:Leukemoid Reaction / Q000473:pathology*; D022423:Myeloid Cells / Q000473:pathology*; D010920:Placenta / Q000473:pathology*; D011247:Pregnancy
keywords: GATA1; congenital leukemia; transient myeloproliferative disorder; trisomy 21; vasculitis