title: Systemic mastocytosis associated with chronic idiopathic myelofibrosis: a distinct subtype of systemic mastocytosis associated with a [corrected] clonal hematological non-mast [corrected] cell lineage disorder carrying the activating point mutations KITD816V and JAK2V617F.
abstract: In approximately 20 to 30% of patients with systemic mastocytosis (SM), an associated clonal hematological nonmast cell lineage disorder (AHNMD) is diagnosed. Although SM may be considered to be closely related to the myeloproliferative disorders (MPDs), it is unknown whether JAK2(V617F+) MPD may occur as AHNMD in patients with SM. We here describe five patients with SM and co-existing chronic idiopathic myelofibrosis (SM-CIMF). In five of five patients, we detected the SM-related KIT mutation D816V, and in four of five patients, the MPD-related JAK2 mutation V617F. Surprisingly, JAK2(V617F) was found not only in the AHNMD component of the disease but also in microdissected mast cells in all four JAK2(V617F)-positive cases. Conversely, in two of the five patients, KIT(D816V) was found not only in neoplastic mast cells but also in microdissected CD15(+) neoplastic myeloid cells. Control experiments showed that 10 indolent SM patients without associated MPD did not carry the JAK2 mutation V617F and that 15 CIMF patients without SM did not carry the KIT mutation D816V. Altogether, these data suggest that KIT(D816V+) SM can co-exist with JAK2(V617F+) CIMF and that, in some of these SM-CIMF cases, the two mutations are present in the neoplastic cells of both disease components.
authors.affiliation: Institute of Pathology, University of Tübingen, Liebermeisterstrasse 8, D-72076 Tübingen, Germany. klsotlar@med.uni-tuebingen.de
authors.forename: Karl
authors.initials: K
authors.lastname: Sotlar
authors.forename: Anja
authors.initials: A
authors.lastname: Bache
authors.forename: Florian
authors.initials: F
authors.lastname: Stellmacher
authors.forename: Burkhard
authors.initials: B
authors.lastname: Bültmann
authors.forename: Peter
authors.initials: P
authors.lastname: Valent
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Horny
mesh_terms: D000328:Adult; D000368:Aged; D019943:Amino Acid Substitution; D001853:Bone Marrow / Q000473:pathology; D001854:Bone Marrow Cells / Q000473:pathology; D019070:Cell Lineage; D002908:Chronic Disease; D002999:Clone Cells; D004273:DNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053614:Janus Kinase 2 / Q000235:genetics*; D008297:Male; D008407:Mast Cells / Q000473:pathology; D034721:Mastocytosis, Systemic / Q000145:classification / Q000150:complications* / Q000235:genetics* / Q000473:pathology; D042282:Microdissection; D008875:Middle Aged; D009841:Oligonucleotides / Q000378:metabolism; D017354:Point Mutation / Q000235:genetics; D016133:Polymerase Chain Reaction; D055728:Primary Myelofibrosis / Q000150:complications* / Q000235:genetics* / Q000473:pathology; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics*; D012680:Sensitivity and Specificity
chemical_list: D004273:DNA, Neoplasm; D009841:Oligonucleotides; C477371:locked nucleic acid; D019009:Proto-Oncogene Proteins c-kit; D053614:Janus Kinase 2