title: WHO-histological criteria for myeloproliferative neoplasms: reproducibility, diagnostic accuracy and correlation with gene mutations and clinical outcomes.
abstract: Bone marrow histology is included in the diagnostic criteria of myeloproliferative neoplasms (MPNs). However, some concerns have emerged about its reproducibility. To evaluate the diagnostic accuracy of histology and to assess its correlation with presence of mutations and clinical outcomes, two pathologists reviewed the bone marrow biopsies corresponding to 211 patients with MPN. Despite the low agreement in the evaluation of individual histopathological characteristics, the concordance among pathologists when establishing the diagnosis was good (Kappa index 0·67). The specificity of histology was 100%, 98·5% and 98% in polycythaemia vera (PV), essential thrombocythaemia (ET) and primary myelofibrosis (PMF), respectively, whereas the sensitivity of histological diagnosis was low in PV and ET (32·5% and 54% respectively) and acceptable in PMF (75%). Thirteen out of 146 (9%) patients with clinical ET were diagnosed as prefibrotic PMF. No histological agreement or MPN otherwise unspecified was more frequently observed in JAK2 V617F-positive ET than in CALR-mutated cases, whereas megakaryocytic abnormalities and prefibrotic PMF were more frequently observed in CALR-mutated ET. In conclusion, histological criteria of MPN have a limited diagnostic accuracy due to low sensitivity. Patients with JAK2 V617F-positive MPN have a heterogeneous histology while CALR-positive ET is associated with megakaryocyte abnormalities and prefibrotic PMF.
authors: Department of Haematology, Hospital del Mar, IMIM, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors: Alberto
authors: A
authors: Alvarez-Larrán
authors: Agueda
authors: A
authors: Ancochea
authors: Mar
authors: M
authors: García
authors: Fina
authors: F
authors: Climent
authors: Francesc
authors: F
authors: García-Pallarols
authors: Anna
authors: A
authors: Angona
authors: Alicia
authors: A
authors: Senín
authors: Carlos
authors: C
authors: Barranco
authors: Luz
authors: L
authors: Martínez-Avilés
authors: Sergio
authors: S
authors: Serrano
authors: Beatriz
authors: B
authors: Bellosillo
authors: Carlos
authors: C
authors: Besses
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D001853:Bone Marrow / Q000473:pathology*; D037282:Calreticulin / Q000235:genetics; D005260:Female; D006801:Humans; D053614:Janus Kinase 2 / Q000235:genetics; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D009196:Myeloproliferative Disorders / Q000235:genetics / Q000473:pathology*; D015588:Observer Variation; D011379:Prognosis; D053628:Receptors, Thrombopoietin / Q000235:genetics
chemical_list: C576483:CALR protein, human; D037282:Calreticulin; D053628:Receptors, Thrombopoietin; C082218:MPL protein, human; C507924:JAK2 protein, human; D053614:Janus Kinase 2
keywords: CALR; JAK2 V617F; bone marrow histology; myelopoliferative neoplasms; prefibrotic myelofibrosis