Polycythemia vera


Blood smear from a patient with polycythemia vera. here are three red blood cell precursors present and slight to moderate anisopoikilocytosis. (Wright-Giemsa stain)
  • Chronic myeloproliferative disorder
  • Abnormal proliferation is seen in all 3 cell lines
  • Typically in elderly
  • Can be asymptomatic or symptomatic
  • Commonly caused by JAK2 mutation

Clinical Features

Erythromelalgia in a patient with longstanding polycythemia vera. Note reddish limbs and swelling..
  • Severe burning pain in the hands or feet accompanied by a reddish or bluish coloration of the skin
  • Suspected with any combination of the following: [1]
    • Abnormally elevated hemoglobin levels (>18 g/dL in men; 16 g/dL in women)
    • Normal oxygen saturation
    • Bleeding complications
    • Portal vein thrombosis
    • Splenomegaly
    • Plethora
    • Pruritus after bathing
  • May develop hyperviscosity syndrome

Differential Diagnosis

Polycythemia (Erythrocytosis)



  • CBC
  • Chem 7
  • ESR
  • EPO decreased
  • Bone marrow biopsy sometimes needed


  • Criteria 1: All category A
  • Criteria 2: First 3 of category A and any 2 of category B
Category A Category B
Increased RBC Mass (Men >18.5, Women >16.5) Thrombocytosis (>400,000)
Normal SPO2 (>92%) Leukocytosis (>12,000)
Splenomegaly Leukocyte Alk Phos >100
Vit B12 >900


  • Phlebotomy with goal hematocrit < 45%[3]
    • Patients with severe plethora, with AMS or vascular compromise can be bled vigorously with removal of 500 mL of whole blood rapidly
    • Otherwise, gradual phlebotomy of 500-1000 mL over 24 hours is preferred in less emergent cases
  • ASA 81mg
  • Myelosuppressive agents (hydroxyurea, interferon-α)
  • If presenting with hyperviscosity syndrome:
    • IVF and phlebotomy


See Also

External Links


  1. http://emedicine.medscape.com/article/205114-differential
  2. Tefferi, A, et al. The 2008 World Health Organization classification system for myeloproliferative neoplasms: order out of chaos. Cancer. 2009; 115(17):3842-7,
  3. Marchioli R et al. Cardiovascular events and intensity of treatment in polycythemia vera. N Engl J Med. 2013; 368(1):22-33.