P o l y c y t h e m i a V e r a
General
• PV is a rare clonal myeloproliferative disorder characterized by increased
production of all myeloid cells (red blood cells, granulocytes, and
megakaryocytes) but with red cells predominating.
• "Polycythemia" means an increase in red blood cell mass. It may be:
• Primary (polycythemia vera): increase in red blood cells caused by an
intrinsic abnormality of myeloid cells (no increase in erythropoietin).
• Secondary: increase in red blood cells caused by increased secretion of
erythropoietin, which may be appropriate (e.g., high-altitude living) or
inappropriate (e.g., tumor-related).
• To diagnose PV, need either
(1) A1, A2, and A3, or
(2) A1, A2, and any two from B:
A (major) criteria:
A1 Increased RBC mass
A2 Normal O2 saturation in blood
A3 Splenomegaly
B (minor) criteria:
B1 Thrombocytosis
B2 High WBC without infection
B3 Increased leukocyte alkaline phosphatase level without infection
B4 Increased serum B12 level
Clinical Features
Age
• Peak age = 60
Symptoms
• Headache, weakness, pruritis, dizziness (increased blood volume)
• Symptoms of vascular stasis, thrombosis, infarction (increased blood
viscosity)
Signs
• Hepatosplenomegaly
• Plethora (ruddiness)
Morphology
Blood
• Early: RBC increased with slight poikilocytosis
• Later: RBC decreased with microcytic, hypochromic anemia
Bone marrow
• Hypercellular
• Panmyelosis (increase in all myeloid cell lines: erythroid, megakaryocytic,
neutrophilic)
Laboratory Findings
• Hgb increased (early) and RBC increased
• WBC increased
• Platelet count normal to increased
• Erythropoietin level decreased
Treatment and Prognosis
• Treatment usually involves phlebotomy, with or without myelosuppressive
drugs (chemotherapy).
• Survival is long (average 9-14 years). Dangers include thrombosis,
hemorrhage, and transformation to acute leukemia.
