Table Classification of Myeloproliferative Neoplasms Disorder Predominant Feature Essential thrombocythemia Thrombocytosis Sometimes leading to bone marrow fibrosis Primary myelofibrosis Anemia, leukocytosis, thrombocytosis, and bone marrow fibrosis with extramedullary hematopoiesis Polycythemia vera Erythrocytosis usually with concurrent increased WBC and platelet counts and sometimes extramedullary hematopoiesis Chronic myeloid leukemia Granulocytosis and thrombocytosis More Information Tremblay D, Yacoub A, Hoffman R: Overview of myeloproliferative neoplasms.