PolyCythaemia

Polycythaemia definition: raised haemoglobin

Causes

• Primary Polycythaemia Vera- Haematological cancer

• Secondary

  • Compensatory mechanism for heart or lung failure: 

• COPD

• CHF

• • Increased EPO

    • Drug abuse (famously Lance Armstrong)

    • Renal Cancer 

• Pseudopolycythaemia

  • Dehydration: haemoglobin level raised due to increased concentration without being truly raised

Assessment

EPO can be used to differentiate between a primary (pituitary) source or secondary source. 

PolyCythaemia VERA

Exam Cram

• Primary Polycythaemia vera (PV) is a haematopoietic malignancy producing high red blood cells

• Presentation: stroke, hyper-viscosity: headaches, rash; splenomegaly

• Diagnosis: JAK-2 mutation (90% sensitivity)+ raised Hb

• Management: hydroxyurea, venesection

Outline

Assessment 

History

• Headaches , TIA/ stroke, 

• Subacute onset: weeks/ months

Examination

• Splenomegaly

Investigations

• Raised Hb, haematocrit, viscosity and platelets

• Low ferritin & EPO

• JAK-2 positive

Diagnosis 

Diagnostic Criteria (WHO- not independently verified)

Major criteria

• JAK2 Mutation

• Increased RCV or Hb > 18.5 (M) or > 16.5 (F)

Minor Criteria

• Marrow morphology

• EPO low

• Endogenous erythroid colony formation in vitro

Management

Long term

• Phlebotomy

• Aspirin

• Hydroxyurea

Page written in 2025. 

References and Resources

1. https://ashpublications.org/blood/article/122/11/1881/31857/Evaluation-of-WHO-criteria-for-diagnosis-of

Links

• Physiology: Haematopoietic-immune systems

• Pathology: cancer

• Specialty: haematology