title: Myelomastocytic leukemia: myeloid neoplasm characterized by partial differentiation of mast cell-lineage cells.
abstract: A novel subtype of myeloid leukemia exhibiting a partial differentiation of mast cell-lineage cells is described. The disease is characterized by an increase in myeloblasts as well as an increase in immature (blast-like) metachromatic cells (>10% in bone marrow or blood smears). Metachromatic cells express KIT (CD117) and tryptase, but lack basophil-related antigens. In contrast to mast cell leukemia/systemic mastocytosis, metachromatic cells do not express CD2 or CD25, do not form multifocal dense aggregates in the bone marrow, and do not exhibit transforming mutations at codon 816 of c-kit. In the few patients recorded so far, a complex karyotype without recurring anomaly was found. The prognosis appears to be grave, although complete remission in response to chemotherapy has been described.
authors.affiliation: Department of Internal Medicine I, Division of Hematology and Hemostaseology, University of Vienna, Austria. peter.valent@akh-wien.ac.at
authors.forename: Peter
authors.initials: P
authors.lastname: Valent
authors.forename: Puchit
authors.initials: P
authors.lastname: Samorapoompichit
authors.forename: Wolfgang R
authors.initials: WR
authors.lastname: Sperr
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Horny
authors.forename: Klaus
authors.initials: K
authors.lastname: Lechner
mesh_terms: D002454:Cell Differentiation; D019070:Cell Lineage; D003937:Diagnosis, Differential; D006801:Humans; D007951:Leukemia, Myeloid / Q000145:classification* / Q000175:diagnosis / Q000473:pathology*; D008407:Mast Cells / Q000473:pathology; D008415:Mastocytosis / Q000175:diagnosis / Q000473:pathology*; D011379:Prognosis