The myeloproliferative disorders
| Polycythemia vera is a clonal disorder of the hematopoietic stem cell in which the dominant feature is autonomous red cell proliferation resulting in an elevated red cell mass. Granulocytosis, thrombocytosis and splenomegaly are also commonly seen. Symptoms, including dizziness, headaches and tinnitus result from hyperviscosity secondary to the increased hematocrit. Patients are at increased risk for thrombosis (etiology unknown) and bleeding (in part, secondary to platelet dysfunction). In about 1-2% of patients, the disease evolves into acute leukemia. |