title: [Infant leukemia with t(1;22) presenting proliferation of erythroid and megakaryocytic cell lineages].
abstract: We report a case of infant leukemia with the proliferation of both erythroblast and megakaryoblast lineages. The blasts became double-positive for both erythroblastic and megakaryoblastic surface markers at the time of bone marrow relapse. A 9-month-old girl was admitted to our hospital presenting chiefly poor with weight gain and anemia. She also had splenomegaly, pleural effusion, leukocytosis, and thrombocytopenia. A bone marrow specimen showed 53.2% erythroblasts (PAS positive, alpha-NA positive, CD41 negative, MPO negative) and 20.4% megakaryoblasts with marked cytoplasmic blebs. We examined specimens by two-color flow cytometric analysis. At the onset, CD41+ glycophorin A- fraction and CD41- glycophorin A+ fraction were two major components. At the bone marrow relapse, the majority of blasts had altered to double-positive. Chromosomal analysis showed t (1; 22) (p13; q13), which has been reported to be specific for acute megakaryoblastic leukemia (M7) in infants. We reasoned that a leukemia had occurred in this patient at a progenitor cell level common to both erythroid and megakaryocytic lineages.
authors.affiliation: Department of Pediatrics, Ibaraki Children's Hospital.
authors.forename: M
authors.initials: M
authors.lastname: Oshima
authors.forename: T
authors.initials: T
authors.lastname: Fukushima
authors.forename: K
authors.initials: K
authors.lastname: Koike
authors.forename: C
authors.initials: C
authors.lastname: Hoshida
authors.forename: I
authors.initials: I
authors.lastname: Izumi
authors.forename: M
authors.initials: M
authors.lastname: Tsuchida
mesh_terms: D001854:Bone Marrow Cells / Q000166:cytology; D002455:Cell Division; D002878:Chromosomes, Human, Pair 1; D002892:Chromosomes, Human, Pair 22; D004900:Erythroblasts / Q000473:pathology*; D005260:Female; D006801:Humans; D007223:Infant; D007947:Leukemia, Megakaryoblastic, Acute / Q000235:genetics / Q000473:pathology*; D008533:Megakaryocytes / Q000473:pathology*; D014178:Translocation, Genetic