Polycythaemia Rubra Vera

• neoplastic myeloproliferative disorder
• increase in bone marrow erythropoeisis

Clinical Features

• equally male and females
• typically over 55
• ruddy complexion
• conjunctival suffusion
• headaches
• visual disturbances
• thrombosis
• haemorrhage (esp. GI)
• peptic ulcer - increased histamine from basophils
• pruritus, gout - excess uric acid production
• enlarged spleen (75%) - distinguishes from other causes of polycythaemia

Laboratory Features

• FBC
  • Raised haematocrit
  •  haemoglobin
  • red cell count
  • red cell mass
  • Increased white cells and/or platelets (75%)
• Neutrophil alkaline phosphatase score (NAP score) increased
• Serum B₁₂, B₁₂ binding increased
• Serum uric acid increased
• Serum erythropoeitin low
• Bone marrow
  • hypercellular
  • prominent megakaryocytes
  • iron stores depleted
  • mildly increased reticulin
• Abdominal USS
  • enlarged spleen
  • excludes renal disease
• Chest X-ray - normal
  • excludes lung disease
• Culture of peripheral blood
  • spontaneous formation of erythroid colonies

Differential

True polycythaemia

• Primary - polycythaemia rubra vera
• Secondary
  • appropriate increase in EPO
    • high altitude
    • cyanotic congenital heart disease
    • chronic lung disease
    • increased haemoglobin affinity for oxygen
  • inappropriate EPO
    • renal disease
      • hypernephroma
      • renal cyst
      • hydronephrosis
    • uterine myoma
    • other tumours
      • HCC
      • bronchial carcinoma

Relative / Spurious polycythaemia

• plasma volume depletion
• stress
  • esp. male smokers
• dehydration
• diuretic therapy

Treatment

• prevent clotting
  • aspirin 75mg / day
  • reduce cell counts
• Reduced packed cell volume
  • venesection
  • chemotherapy
    • hydroxyurea
  • radiotherapy
    • ³²P

Prognosis

• Median survival 16 years
• 30% develop myelofibrosis
• Acute myeloid leukaemia develops in up to 5%
  • may be related to ³²P / chemotherapy

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