Abstract

Polycythemia vera (PV), the archetypal Philadelphia chromosome-negative (Ph-) myeloproliferative neoplasm (MPN), has an estimated prevalence in the U.S. of 38-57 per 100,000 individuals. PV is generally a disease of older individuals, with a quarter of affected individuals under 50 at diagnosis and only 10 percent under 40. There is no gender preference. Palpable splenomegaly is found in approximately 40 percent of patients at diagnosis, and 10-15 percent present with thrombosis. Pruritus and vasomotor symptoms occur in about a third of patients.