Table 1. The 2008 WHO classification scheme for myeloid neoplasms

Disease

% Marrow blasts

Blood counts

BM cellularity

1. Acute myeloid leukemia (AML)

Increased >20%

WBC variable, usually anemia and thrombocytopenia

Usually increased

2. Myelodysplastic syndromes (MDS)

Normal or increased <20%

cytopenia(s)

Increased, occasionally normocellular or hypocellular

3. Myeloproliferative neoplasms (MPN)

 

Normal or slightly increased; <10% in chronic phase

Variable, one or more myeloid lineage usually initially increased

Usually increased, often normal in ET

   3.1 Chronic myelogenous leukemia

 

 

 

   3.2 Polycythemia vera

 

 

 

   3.3 Essential thrombocythemia

 

 

 

   3.4 Primary myelofibrosis

 

 

 

   3.5 Chronic neutrophilic leukemia

 

 

 

   3.6 Chronic eosinophilic leukemia,

        not otherwise categorized

 

 

 

   3.7 Hypereosinophilic syndrome

 

 

 

   3.8 Mast cell disease

 

 

 

   3.9 MPNs, unclassifiable

 

 

 

 

 

 

 

4. MDS/MPN

Normal or slightly increased; <20%

Variable, WBC usually increased

Increased

   4.1 Chronic myelomonocytic leukemia

 

 

 

   4.2 Juvenile myelomonocytic leukemia

 

 

 

   4.3 Atypical chronic myeloid leukemia

 

 

 

   4.4 MDS/MPN, unclassifiable

 

 

 

 

 

 

 

5. Myeloid neoplasms associated with

   eosinophilia and abnormalities

   of PDGFRA, PDGFRB, or FGFR1

Normal or slightly increased; <20% in chronic phase

Eosinophilia

(กร1.5x109/L)

 

Increased

   5.1 Myeloid neoplasms associated

        with PDGFRA rearrangement

     

   5.2 Myeloid neoplasms associated

        with PDGFRB rearrangement

     

   5.3 Myeloid neoplasms associated

        with FGFR1 rearrangement

      (8p11 myeloproliferative syndrome)

     

 

Table 2. The 2008 WHO diagnostic criteria for polycythemia vera,

essential thrombocythemia, and primary myelofibrosis

2008 WHO diagnostic criteria
    Polycythemia vera a   Essential thrombocythemia a   Primary myelofibrosis a
Major criteria 1 Hgb >18.5 g dl-1 (men)
>16.5 g dl-1 (women)
or
Hgb or Hct >99th percentile
of reference range for age,
sex or altitude of residence
or
Hgb>17 g dl-1 (men),
or>15 g dl-1 (women)
if associated with a sustained
increase of greater than or equal to2 g dl-1 from baseline
that cannot be attributed to
correction of iron deficiency
or
Elevated red cell mass
>25% above mean normal
predicted value
1 Platelet count greater than or equal to450 times 109 l-1 1 Megakaryocyte proliferation
and atypiab accompanied by either
reticulin and/or collagen fibrosis,
or
In the absence of reticulin fibrosis,
the megakaryocyte changes must
be accompanied by increased
marrow cellularity, granulocytic
proliferation and often decreased
erythropoiesis (i.e. pre-fibrotic PMF).
  2 Presence of JAK2V617F
or similar mutation
2 Megakaryocyte proliferation with
large and mature morphology.
No or little granulocyte or erythroid
Proliferation.
2 Not meeting WHO criteria for CML,
PV, MDS, or other myeloid neoplasm
      3 Not meeting WHO criteria for CML, PV, PMF, MDS or other myeloid neoplasm 3 Demonstration of JAK2V617F
or other clonal marker
or no evidence of reactive marrow fibrosis
      4 Demonstration of JAK2V617F
or other clonal marker
or no evidence of reactive thrombocytosis
   
             
Minor criteria 1 BM trilineage myeloproliferation     1 Leukoerythroblastosis
  2 Subnormal serum Epo level     2 Increased serum LDH
  3 EEC growth     3 Anemia
          4 Palpable splenomegaly

 

Abbreviations: CML, chronic myelogenous leukemia; EEC, endogenous erythroid colony; Epo, erythropoietin;

Hct, hematocrit; Hgb, hemoglobin; LDH, lactate dehydrogenase; MDS, myelodysplastic syndrome;

WHO, World Health Organization.

 

a Diagnosis of polycythemia vera (PV) requires meeting either both major criteria and one minor criterion

or the first major criterion and 2 minor criteria. Diagnosis of essential thrombocythemia requires meeting

all four major criteria. Diagnosis of primary myelofibrosis (PMF) requires meeting all three major criteria

and two minor criteria.

 

b Small to large megakaryocytes with an aberrant nuclear/cytoplasmic ratio and hyperchromatic

and irregularly folded nuclei and dense clustering.

 

Unfortunately we are unable to provide accessible alternative text for this. If you require assistance to access this image, please contact help@nature.com or the author

Diagnostic algorithm for suspected polycythemia vera. Key: PV, polycythemia vera; SP, secondary polycythemia; CP, congenital polycythemia; BM, bone marrow; V617F, JAK2V617F; Epo, erythropoietin; EpoR, erythropoietin receptor; VHL, von Hippel–Lindau; c/w, consistent with.

 

Unfortunately we are unable to provide accessible alternative text for this. If you require assistance to access this image, please contact help@nature.com or the author

Diagnostic algorithm for suspected essential thrombocythemia. Key: PV, polycythemia vera; ET, essential thrombocythemia; PMF, primary myelofibrosis; CML, chronic myeloid leukemia; MDS, myelodysplastic syndrome; MPN, myeloproliferative neoplasm; WHO, World Health Organization; RT, reactive thrombocytosis; FISH, fluorescent in situ hybridization; Ph, Philadelphia; BM, bone marrow; V617F, JAK2V617F.

 

Unfortunately we are unable to provide accessible alternative text for this. If you require assistance to access this image, please contact help@nature.com or the author

Diagnostic algorithm for suspected primary myelofibrosis. Key: PMF, primary myelofibrosis; CML, chronic myeloid leukemia; MDS, myelodysplastic syndrome; FISH, fluorescent in situ hybridization; Ph, Philadelphia; BM, bone marrow; V617F, JAK2V617F.

 

Unfortunately we are unable to provide accessible alternative text for this. If you require assistance to access this image, please contact help@nature.com or the author

Diagnostic algorithm for primary eosinophilia (greater than or equal to1.5 times 109 l-1 blood eosinophil count). Key: CEL, chronic eosinophilic leukemia; HES, hypereosinophilic syndrome; FISH, fluorescent in situ hybridization; BM, bone marrow; PB, peripheral blood; PDGFR, platelet-derived growth factor receptor; FGFR, fibroblast growth factor receptor. *T-cell receptor gene rearrangement studies and immunophenotyping.

 

FROM:  Classification and diagnosis of myeloproliferative neoplasms:

           The 2008 World Health Organization criteria and point-of-care diagnostic algorithms

A Tefferi and J W Vardiman. Leukemia (2008) 22, 14-22