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World Health Organization (WHO) Diagnostic Criteria for Polycythemia Vera
Checks whether major and minor WHO criteria for polycythemia vera are met.
World Health Organization (WHO) Diagnostic Criteria for Polycythemia Vera
Major criterion 1: Hgb >16.5 g/dL (men) / >16.0 g/dL (women), or Hct >49% (men) / >48% (women), or increased red cell mass
Major criterion 2: bone marrow biopsy showing hypercellularity with trilineage growth (panmyelosis), including prominent erythroid, granulocytic, and megakaryocytic proliferation with pleomorphic, mature megakaryocytes
Major criterion 3: presence of JAK2 V617F or JAK2 exon 12 mutation
Minor criterion: subnormal serum erythropoietin (EPO) level
ResultCriteria not met
Diagnostic criteria for polycythemia vera are not satisfied with the findings entered; consider other myeloproliferative neoplasms or secondary/relative erythrocytosis.
- Major criteria met
- 0 / 3
- Minor criterion met
- No
When to use
- Confirming a diagnosis of polycythemia vera in a patient with erythrocytosis, once secondary causes have been considered.
Formula
Diagnosis requires all 3 major criteria (elevated Hgb/Hct or red cell mass; characteristic bone marrow panmyelosis; JAK2 mutation), OR major criteria 1 and 2 plus the minor criterion (subnormal serum erythropoietin).
Pearls and pitfalls
- JAK2 V617F or exon 12 mutations are present in over 98% of true polycythemia vera; a negative JAK2 result makes the diagnosis unlikely but does not exclude rare mutation-negative cases when marrow and EPO findings support it.
- Bone marrow biopsy (major criterion 2) may be waived by some experts when major criterion 1 and 3 are striking and EPO is subnormal, but the formal WHO algorithm as codified requires it in the 3-major or 2-major-plus-minor pathway shown here.