RT Book, Section A1 Lichtman, Marshall A. A1 Kaushansky, Kenneth A1 Prchal, Josef T. A1 Levi, Marcel M. A1 Burns, Linda J. A1 Linch, David C. SR Print(0) ID 1189334457 T1 Essential Thrombocythemia T2 Williams Manual of Hematology, 10e YR 2022 FD 2022 PB McGraw-Hill Education PP New York, NY SN 9781264269204 LK hemonc.mhmedical.com/content.aspx?aid=1189334457 RD 2024/04/23 AB The upper limit of a normal platelet count is usually between 350 × 109/L and 450 × 109/L depending on the clinical laboratory and specific method used.Table 43–1 presents the major causes of elevation of the platelet count above the normal limit. Only essential thrombocythemia (ET) is discussed here; familial and reactive thrombocytosis are discussed in Chapter 75, Hereditary and Reactive (Secondary) Thrombocytosis.