title: Stem cell factor-induced bone marrow mast cell hyperplasia mimicking systemic mastocytosis (SM): histopathologic and morphologic evaluation with special reference to recently established SM-criteria.
abstract: Although systemic mastocytosis (SM) is a well-defined hematologic neoplasm, it is sometimes difficult to discriminate between SM and a reactive mast cell (MC) hyperplasia. We describe a patient with aplastic anemia who was treated with recombinant stem cell factor (SCF). In response to SCF, the patient showed transient hematologic improvement and developed a marked increase in MC as well as a transient increase in serum tryptase. Histologic and immunohistochemical examination revealed a huge increase in MC in the bone marrow with focal infiltrates similar to SM. However, most of the SM-criteria were not met: First, MC showed normal cytomorphological characteristics without significant atypias (no cytoplasmic extensions, no oval nuclei, no hypogranulated cytoplasm). Furthermore, bone marrow MC were CD2- and CD25-negative and did not exhibit the C-KIT 2468 A-->T mutation (Asp-816-Val). After discontinuation of SCF the MC hyperplasia resolved confirming its reactive nature. Based on our case and similar cases mimicking mastocytosis, it seems of importance to apply recently established SM criteria in order to discriminate between reactive MC hyperplasia and true mastocytosis with certainty.
authors: Department of Internal Medicine 1, University of Vienna, Währinger Gürtel, Austria.
authors: John-Hendrik
authors: JH
authors: Jordan
authors: Gerit-Holger
authors: GH
authors: Schernthaner
authors: Robert
authors: R
authors: Fritsche-Polanz
authors: Wolfgang R
authors: WR
authors: Sperr
authors: Manuela
authors: M
authors: Födinger
authors: Andreas
authors: A
authors: Chott
authors: Klaus
authors: K
authors: Geissler
authors: Klaus
authors: K
authors: Lechner
authors: Hans-Peter
authors: HP
authors: Horny
authors: Peter
authors: P
authors: Valent
mesh_terms: D000741:Anemia, Aplastic / Q000150:complications / Q000188:drug therapy; D001854:Bone Marrow Cells / Q000187:drug effects / Q000473:pathology; D020732:Cytogenetic Analysis; D003937:Diagnosis, Differential; D006801:Humans; D006965:Hyperplasia / Q000139:chemically induced / Q000175:diagnosis* / Q000473:pathology; D016130:Immunophenotyping; D008297:Male; D008407:Mast Cells / Q000187:drug effects* / Q000473:pathology; D008415:Mastocytosis / Q000175:diagnosis*; D008875:Middle Aged; D012697:Serine Endopeptidases / Q000097:blood; D019089:Stem Cell Factor / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D053802:Tryptases
chemical_list: D019089:Stem Cell Factor; D012697:Serine Endopeptidases; D053802:Tryptases