Polycythemia Vera

This chapter covers testing and management of polycythemia vera (PV). PV predominantly occurs in older males and is a potent provoking factor for venous thromboembolism (VTE); the major cause of morbidity and mortality in PV is thrombosis, which is related to the intensity of hematocrit control. Tight hematocrit control is clearly effective at ameliorating this risk, reducing the rate of major deep venous thrombosis to <0.5% per year. The optimal therapeutic hematocrit target in patients with PV is debated; traditionally, a lower target is often recommended for female patients compared to male ones. Most PV-specific therapies result in survival prolongation through reduction of thrombotic risk. In addition, it is a common misconception that the presence of marrow reticulin fibrosis in patients with PV represents transformation to post-PV myelofibrosis. Acute leukemia is a rare but devastating complication of PV.