RT Book, Section A1 Lichtman, Marshall A. A1 Kaushansky, Kenneth A1 Prchal, Josef T. A1 Levi, Marcel M. A1 Burns, Linda J. A1 Armitage, James O. SR Print(0) ID 1133363268 T1 Polyclonal Polycythemias (Primary and Secondary) T2 Williams Manual of Hematology, 9e YR 2017 FD 2017 PB McGraw-Hill Education PP New York, NY SN 9781259642470 LK hemonc.mhmedical.com/content.aspx?aid=1133363268 RD 2024/10/09 AB Polycythemia, also referred to as erythrocytosis, is characterized by an increased red cell mass. There is no consensus on terminology (ie, primary familial polycythemia but postrenal transplantation erythrocytosis). Polycythemias can be primary or secondary and can be inherited or acquired.Classification of polycythemic disorders appears in Table 2–2 in Chap. 2.Primary polycythemias are caused by somatic or germline mutations within hematopoietic stem cells or erythroid progenitors that result in an augmented response to erythropoietin. This response is inappropriate; that is, it is not a compensation for hypoxia.Secondary polycythemias are caused by either an appropriate (compensatory) or inappropriate increase in the red cell mass as a result of augmented levels of erythropoietin.