title: The origin of neoplastic mast cells in systemic mastocytosis with AML1/ETO-positive acute myeloid leukemia.
abstract: OBJECTIVE
  Systemic mastocytosis with associated clonal hematological non-mast cell lineage disease (SM-AHNMD) is a distinct entity that was defined by World Health Organization. Systemic mastocytosis with acute myeloid leukemia (AML) is frequently seen among SM-AHNMD. However, the pathogenesis or origin of neoplastic mast cells has not been fully elucidated in this category of diseases.
  
  
  METHODS
  We examined KIT mutation, chimeric status, and AML1/ETO mRNA concerning mast cells and immature hematopoietic cells of the bone marrow in a patient with systemic mastocytosis with AML1/ETO-positive AML following allogeneic hematopoietic stem cell transplantation (HSCT).
  
  
  RESULTS
  Mast cells of the patient displayed KIT D816Y mutation, and were derived from the recipient. In contrast, immature hematopoietic cells as defined by CD34+ CD117+ were derived from the donor, which did not possess detectable KIT D816Y mutation. The ratio of AML1/ETO to 18S rRNA of the mast cells was 7.53, whereas that of immature hematopoietic cells was 1.67.
  
  
  CONCLUSIONS
  In a patient with SM-AHNMD who underwent allogeneic HSCT, the major source of the detectable AML1/ETO mRNA of the bone marrow after transplantation was neoplastic mast cells with KIT mutation, which were thought to be derived from CD34+ CD117+ immature leukemic cells of the recipient.
authors.affiliation: Department of Hematology and Oncology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Sumimasa
authors.initials: S
authors.lastname: Nagai
authors.forename: Motoshi
authors.initials: M
authors.lastname: Ichikawa
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Takahashi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sato
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Yokota
authors.forename: Kumi
authors.initials: K
authors.lastname: Oshima
authors.forename: Koji
authors.initials: K
authors.lastname: Izutsu
authors.forename: Akira
authors.initials: A
authors.lastname: Hangaishi
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Kanda
authors.forename: Toru
authors.initials: T
authors.lastname: Motokura
authors.forename: Shigeru
authors.initials: S
authors.lastname: Chiba
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Yatomi
authors.forename: Mineo
authors.initials: M
authors.lastname: Kurokawa
mesh_terms: D000328:Adult; D018952:Antigens, CD34; D019070:Cell Lineage; D050676:Core Binding Factor Alpha 2 Subunit; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D015470:Leukemia, Myeloid, Acute / Q000209:etiology* / Q000473:pathology; D008407:Mast Cells / Q000473:pathology*; D034721:Mastocytosis, Systemic / Q000145:classification / Q000150:complications / Q000473:pathology*; D009154:Mutation; D015514:Oncogene Proteins, Fusion; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics; D000075142:RUNX1 Translocation Partner 1 Protein; D014184:Transplantation, Homologous
chemical_list: C107844:AML1-ETO fusion protein, human; D018952:Antigens, CD34; D050676:Core Binding Factor Alpha 2 Subunit; D015514:Oncogene Proteins, Fusion; D000075142:RUNX1 Translocation Partner 1 Protein; D019009:Proto-Oncogene Proteins c-kit