title: Chronic idiopathic myelofibrosis: clinicopathologic features, pathogenesis, and prognosis.
abstract: BACKGROUND
  Chronic idiopathic myelofibrosis (CIMF) is a clonal myeloproliferative disease characterized by panmyelosis with intact maturation, progressive bone marrow fibrosis, and multiorgan extramedullary hematopoiesis.
  
  
  OBJECTIVE
  This review article aims to summarize the recent updates regarding the clinicopathologic features, molecular pathogenesis, cytogenetic abnormalities, diagnostic criteria, new diagnostic ancillary tests, and prognostic factors of CIMF.
  
  
  METHODS
  Important relevant articles indexed in PubMed/MEDLINE (National Library of Medicine) through the end of 2005 and referenced medical texts.
  
  
  CONCLUSIONS
  Because CIMF has a variety of clinical presentations, diagnosis may be challenging; the prefibrotic stage of CIMF has always been a challenging disease for pathologists to diagnose accurately. The recently proposed European Clinical and Pathological criteria can be helpful in the diagnosis of CIMF, especially in its prefibrotic stage. The enumeration of CD34-positive cells in the peripheral blood and the presence of circulating endothelial progenitor cells are the new important ancillary tests for the diagnosis of a small subset of patients with CIMF with atypical presentation. The recent discovery of the new mutation affecting the Janus tyrosine kinase 2 (JAK2V617F), more frequently observed in patients with polycythemia vera, is seen in approximately 35% to 57% of patients with CIMF. This mutation can serve as another diagnostic tool. Important factors affecting prognosis in CIMF are anemia, age of the patient, white blood cell count, degree of fibrosis, and number of blasts in the peripheral blood.
authors.affiliation: Department of Pathology and Laboratory Medicine, Baylor College of Medicine, Houston, Tex, USA.
authors.forename: Arsalan
authors.initials: A
authors.lastname: Ahmed
authors.forename: Chung-Che Jeff
authors.initials: CC
authors.lastname: Chang
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D001853:Bone Marrow / Q000473:pathology*; D006411:Hematopoiesis, Extramedullary; D006801:Humans; D053614:Janus Kinase 2; D017354:Point Mutation; D055728:Primary Myelofibrosis / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D011379:Prognosis; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D015415:Biomarkers; D011518:Proto-Oncogene Proteins; D011505:Protein-Tyrosine Kinases; C507924:JAK2 protein, human; D053614:Janus Kinase 2