ToolsCalculators
World Health Organization (WHO) Diagnostic Criteria for Polycythemia Vera
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.