{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,28]],"date-time":"2026-07-28T05:02:45Z","timestamp":1785214965641,"version":"3.55.0"},"reference-count":22,"publisher":"Georg Thieme Verlag KG","issue":"11","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Am J Perinatol"],"published-print":{"date-parts":[[2026,8]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>This study was aimed to underscore the value of placental examination in identifying transient abnormal myelopoiesis (TAM), particularly in neonates with previously unsuspected Down syndrome (DS), and to demonstrate how such placental findings can guide timely clinical diagnosis when there is no antenatal suspicion.<\/jats:p>\n                  <jats:p>This short communication describes the clinical, hematological, and placental pathological findings in a neonate born without prior antenatal suspicion of DS. Particular emphasis is placed on the identification of TAM and associated myeloid cell thrombus (MCT) within the placenta and their relevance in prompting further clinical evaluation.<\/jats:p>\n                  <jats:p>The placental weight and dimensions were 330\u2009g and 13\u2009cm\u2009\u00d7\u200912\u2009cm, and the disc was unremarkable on macroscopic examination. The umbilical cord showed thrombus in one of the vessels. On microscopy, the muscularized placental fetal vessels showed evidence of leukocytosis with left shift of hematopoietic elements inclusive of blast forms. Many nucleated red blood cells along with platelets and fibrin were also noted. These hematopoietic precursors were seen forming organized thrombi causing segmental high-grade lesions of fetal vascular malperfusion. The umbilical artery in the umbilical cord showed MCT (positive for CD 34 and CD 117 on immunohistochemistry). Hematological investigations with flow cytometry assisted in diagnosis, which was confirmed by genetic testing.<\/jats:p>\n                  <jats:p>In situations where DS is not clinically suspected antenatally, recognition of TAM\u2014especially when accompanied by MCT\u2014on placental examination may serve as the first and only clue prompting clinicians to investigate for DS. This case underscores the pivotal role of placental pathology in facilitating early detection and appropriate management of such neonates.<\/jats:p>","DOI":"10.1055\/a-2795-4705","type":"journal-article","created":{"date-parts":[[2026,2,11]],"date-time":"2026-02-11T00:12:57Z","timestamp":1770768777000},"page":"1551-1555","source":"Crossref","is-referenced-by-count":0,"title":["Transient Abnormal Myelopoiesis with Myeloid Cell Thrombus in a Case of Down Syndrome: A Rare Placental Finding"],"prefix":"10.1055","volume":"43","author":[{"given":"Padmavathi S.","family":"Kamath","sequence":"additional","affiliation":[{"name":"Department of Pathology, St. John's Medical College, Bangalore, Karnataka, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4426-6914","authenticated-orcid":false,"given":"Gayatri","family":"Ravikumar","sequence":"additional","affiliation":[{"name":"Department of Pathology, St. John's Medical College, Bangalore, Karnataka, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A. M.","family":"Shanthaladevi","sequence":"additional","affiliation":[{"name":"Department of Transfusion Medicine and Immunohematology, St. John's Medical College Hospital, Bangalore, Karnataka, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Veronica Preeta","family":"Tilak","sequence":"additional","affiliation":[{"name":"Division of Molecular Biology and Genetics, Department of Genetics, St. John's Medical College, Bangalore, Karnataka, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bada Shekarappa","family":"Chandrakala","sequence":"additional","affiliation":[{"name":"Department of Neonatology, St. John's Medical College Hospital, Bangalore, Karnataka, India"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"194","published-online":{"date-parts":[[2026,2,10]]},"reference":[{"issue":"09","key":"ref1","doi-asserted-by":"crossref","first-page":"1301","DOI":"10.1007\/s00431-011-1624-1","article-title":"Hematological disorders 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placentas: histopathological and immunohistochemical findings using proliferating cell nuclear antigen","volume":"12","author":"F Qureshi","year":"1997","journal-title":"Fetal Diagn Ther"},{"issue":"07","key":"ref10","doi-asserted-by":"crossref","first-page":"678","DOI":"10.1053\/plac.2000.0553","article-title":"Histomorphological features of chorionic villi at 10-14 weeks of gestation in trisomic and chromosomally normal pregnancies","volume":"21","author":"L Roberts","year":"2000","journal-title":"Placenta"},{"issue":"07","key":"ref11","doi-asserted-by":"crossref","first-page":"433","DOI":"10.1038\/ncponc0876","article-title":"Severe TMD\/AMKL with GATA1 mutation in a stillborn fetus with Down syndrome","volume":"4","author":"B Heald","year":"2007","journal-title":"Nat Clin Pract Oncol"},{"issue":"10","key":"ref12","doi-asserted-by":"crossref","first-page":"1001","DOI":"10.1136\/adc.61.10.1001","article-title":"Congenital leukaemia: an unusual cause of stillbirth","volume":"61","author":"E S Gray","year":"1986","journal-title":"Arch Dis Child"},{"issue":"05","key":"ref13","doi-asserted-by":"crossref","first-page":"366","DOI":"10.2350\/14-04-1476-CR.1","article-title":"Trisomy 21-associated transient abnormal myelopoiesis involving the maternal space of the placenta: a case report and literature review","volume":"17","author":"Q Dai","year":"2014","journal-title":"Pediatr Dev Pathol"},{"issue":"03","key":"ref14","doi-asserted-by":"crossref","first-page":"231","DOI":"10.2350\/14-11-1575-CR.1","article-title":"Extensive placental choriovascular infiltration by maturing myeloid cells in down syndrome-associated transient abnormal myelopoiesis","volume":"18","author":"S Ravishankar","year":"2015","journal-title":"Pediatr Dev Pathol"},{"issue":"05","key":"ref15","doi-asserted-by":"crossref","first-page":"510","DOI":"10.1002\/ajmg.1320460509","article-title":"Hematologic abnormalities in children with Down 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