Polycythaemia vera

Polycythaemia vera (previously called polycythaemia rubra vera) is a myeloproliferative disorder caused by clonal proliferation of a marrow stem cell leading to an increase in red cell volume, often accompanied by overproduction of neutrophils and platelets.

Classification (from the other "Polycythemia" page)

Relative

• dehydration
• Gaisböck’s syndrome (stress)

Primary

• polycythaemia rubra vera (often splenomegaly, raised platelets)

Secondary

• hypoxia
  • smoking
  • chronic obstructive pulmonary disease
  • altitude
  • abnormal haemoglobins
  • sleep apnoea and extreme obesity (Pickwickian)
  • cyanotic heart disease

Excess erythropoietin

• cerebellar haemangioma
• hepatoma
• phaeochromocytoma
• hypernephroma
• polycystic/transplant kidneys; RCC
• uterine leiomyoma/fibroma It has recently been established that a mutation in JAK2 is present in approximately 95% of patients with polycythaemia vera and this has resulted in significant changes to the diagnostic criteria. The incidence of polycythaemia vera peaks in the sixth decade.

Features

• pruritus, typically after a hot bath