title: Systemic mastocytosis in adults: 2012 Update on diagnosis, risk stratification, and management.
abstract: BACKGROUND
  Systemic mastocytosis (SM) results from a clonal proliferation of abnormal mast cells (MC) in one or more extra-cutaneous organs.
  
  
  METHODS
  The major criterion is presence of multifocal clusters of morphologically abnormal MC in the bone marrow. Minor diagnostic criteria include elevated serum tryptase level, abnormal MC expression of CD25 and/or CD2, and presence of KITD816V.
  
  
  METHODS
  The prognostic relevance of the 2008 World Health Organization (WHO) classification of SM has recently been confirmed. Classification of SM patients into indolent (SM), aggressive SM (ASM), SM associated with a clonal non-MC lineage disease (SM-AHNMD) and mast cell leukemia (MCL) subgroups is a useful first step in establishing prognosis.
  
  
  RESULTS
  SM treatment is generally palliative. ISM patients have a normal life expectancy and receive symptom-directed therapy; infrequently, cytoreductive therapy may be indicated for refractory symptoms. ASM patients have disease-related organ dysfunction; interferon-α (±corticosteroids) can control dermatological, hematological, gastrointestinal, skeletal, and mediator-release symptoms, but is hampered by poor tolerability. Similarly, cladribine has broad therapeutic activity, with particular utility when rapid MC debulking is indicated; the main toxicity is myelosuppression. Imatinib has a therapeutic role in the presence of an imatinib-sensitive KIT mutation or in KITD816-unmutated patients. Treatment of SM-AHNMD is governed primarily by the non-MC neoplasm; hydroxyurea has modest utility in this setting.
  Dasatinib's in vitro anti-KITD816V activity has not translated into significant therapeutic activity in most SM patients. In contrast, preliminary data suggest that Midostaurin may produce significant decreases in MC burden in some patients.
authors.affiliation: Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA. pardanani.animesh@mayo.edu
authors.forename: Animesh
authors.initials: A
authors.lastname: Pardanani
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000328:Adult; D001856:Bone Marrow Examination; D019070:Cell Lineage; D017338:Cladribine / Q000009:adverse effects / Q000627:therapeutic use; D002986:Clinical Trials as Topic; D002999:Clone Cells / Q000473:pathology; D019468:Disease Management; D018450:Disease Progression; D006801:Humans; D006918:Hydroxyurea / Q000627:therapeutic use; D016130:Immunophenotyping; D016898:Interferon-alpha / Q000627:therapeutic use; D007946:Leukemia, Mast-Cell / Q000473:pathology; D008407:Mast Cells / Q000737:chemistry / Q000201:enzymology / Q000473:pathology; D034721:Mastocytosis, Systemic / Q000145:classification / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics / Q000628:therapy; D020125:Mutation, Missense; D009928:Organ Specificity; D011379:Prognosis; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics; D018570:Risk Assessment; D019311:Staurosporine / Q000031:analogs & derivatives / Q000627:therapeutic use; D053802:Tryptases / Q000097:blood
chemical_list: D000305:Adrenal Cortex Hormones; D016898:Interferon-alpha; D047428:Protein Kinase Inhibitors; D017338:Cladribine; D019009:Proto-Oncogene Proteins c-kit; D053802:Tryptases; D019311:Staurosporine; C059539:midostaurin; D006918:Hydroxyurea