Diagnostic criteria for MPNs

The diagnosis of MPNs is based on use of the diagnostic criteria from the 2008 WHO classification for myeloid neoplasms.1,2 These criteria use clinical, morphologic, and genetic information to define the 3 main Ph- MPNs as distinct biological entities.1,2

2008 WHO Diagnostic Criteria for Ph- Classic MPNs1,3
All 3 major criteria
+ 2 minor criteria
Major Criteria
  1. Proliferation and atypia of megakaryocytes, with or without reticulin and/or collagen fibrosisa
  2. Does not meet WHO criteria for CML, PV, MDS, or other myeloid neoplasm
  3. JAK2 V617F or other clonal marker or no evidence of reactive marrow fibrosis
Minor Criteria
  1. Leukoerythroblastosis
  2. Inceased serum LDH
  3. Anemia
  4. Palpable splenomegaly
Both major criteria
+ 1 minor criterion
first major criterion
+ 2 minor criteria
Major Criteria
  1. Hb >18.5 g/dL (men)
    or >16.5 g/dL (women)b
  2. JAK2 V617F or similar mutation
Minor Criteria
  1. BM showing hypercellularity for age and trilineage growth (pan-myelosis)
  2. Subnormal serum
    Epo level
  3. EEC growth

BM, bone marrow biopsy specimen; CML, BCR-ABL1 chronic myelogenous leukemia; EEC, endogenous erythroid colonies; Epo, erythropoietin; ET, essential thrombocythemia; Hct, hematocrit; Hb, hemoglobin; LDH, lactate dehydrogenase; MDS, myelodysplastic syndrome; PMF, primary myelofibrosis; PV, polycythemia vera; WHO, World Health Organization.
  • a Presence of megakaryocyte proliferation and atypia (small to large megakaryocytes with an aberrant nuclear/cytoplasmic ratio; hyperchromatic, bulbous, or irregularly folded nuclei; and dense clustering). In the absence of significant reticulin fibrosis, the megakaryocyte changes must be accompanied by an increased bone marrow cellularity characterized by granulocytic proliferation and often decreased erythropoiesis (ie, prefibrotic cellular-phase disease).
  • b Or Hb or Hct >99th percentile of reference range for age, sex, or altitude of residence or Hb >17 g/dL (men) or >15 g/dL (women) if associated with a documented and sustained increase of ≥2 g/dL from baseline that cannot be attributed to correction of iron deficiency or elevated red cell mass >25% above mean normal predicted value.
  1. Vardiman JW, Thiele J, Arber DA, et al. Blood. 2009;114(5):937-951.
  2. Barbui T, Barosi G, Birgegard G, et al. J Clin Oncol. 2011;29(6):761-770.
  3. Vannucchi A, Guglielmelli P, Tefferi A. CA Cancer J Clin. 2009;59(3):171-191.