title: Congenital acute leukemia with initial indolent presentation--a case report.
abstract: BACKGROUND
  Congenital acute leukemia is a rare event, presenting usually as an aggressive disease with a poor prognosis. A differential diagnosis is the transient myeloproliferative disorder observed in Down syndrome. We describe the case of an apparently healthy newborn male child presenting with normal peripheral blood (PB) counts but with a blast population on differentials. The child's condition and the blast population remained unchanged during the first year of life.
  
  
  METHODS
  Bone marrow and PB were morphologically analyzed. Multiparametric flow cytometry was performed at the time of diagnosis and repeated at 1 year. These studies were completed by cytogenetic and molecular analyses.
  
  
  RESULTS
  Bone marrow contained 40% of undifferentiated blasts. Multiparametric flow cytometry showed low expression of CD38, HLA-DR, and CD33 markers. All other markers were negative. Constitutional and blast cell karyotypes were normal. Fluorescence in situ hybridization analysis showed no rearrangement. Molecular studies were negative. The blast percentage remained stable during several months. After 1 year, the PB counts showed thrombocytopenia, with an increase of blast cells exhibiting the same phenotype. Clinically, an enlarged spleen was found. The child did not respond to chemotherapy and only partially to gemtuzumab ozogamicin. A cord blood cell transplantation was finally performed. With a follow-up of 12 months, the child is doing well.
  
  
  CONCLUSIONS
  To our knowledge, this is the first case of congenital acute leukemia with initially indolent course in a newborn without Down syndrome. This observation emphasizes the importance of a careful follow-up.
authors.affiliation: Laboratoire d'Hématologie, Hôpital Nord, Centre Hospitalier Universitaire, Saint Etienne, France. lydia.campos@chu-st-etienne.fr
authors.forename: Lydia
authors.initials: L
authors.lastname: Campos
authors.forename: Nathalie
authors.initials: N
authors.lastname: Nadal
authors.forename: Pascale
authors.initials: P
authors.lastname: Flandrin-Gresta
authors.forename: Christian
authors.initials: C
authors.lastname: Vasselon
authors.forename: Carmen
authors.initials: C
authors.lastname: Aanei
authors.forename: Claire
authors.initials: C
authors.lastname: Berger
authors.forename: Jean Louis
authors.initials: JL
authors.lastname: Stephan
mesh_terms: D036101:Cord Blood Stem Cell Transplantation; D005434:Flow Cytometry; D005500:Follow-Up Studies; D006801:Humans; D007231:Infant, Newborn; D015470:Leukemia, Myeloid, Acute / Q000151:congenital* / Q000175:diagnosis* / Q000628:therapy; D007958:Leukocyte Count; D008297:Male