Chapter 5 - Benign white blood cell and platelet disorders

Abstract

Leukocytosis or elevated white blood cell (WBC) count is a common laboratory finding. Normal WBC differential also changes with age, and proper normal ranges must be established for each laboratory performing such tests. However, leukocytosis is also a feature of leukemias, and thus distinguishing leukemias from other causes of leukocytosis is very important for proper diagnosis and management of patient. Examination of peripheral blood smear along with review of complete blood count analysis is essential for such differentiation, and if necessary, further analysis such as flow cytometry, molecular studies, and possible bone marrow examination must be undertaken. Similarly, platelet disorder such as thrombocytopenia or thrombocytosis may be a benign condition or reflection of a serious condition such as severe thrombocytopenia observed in patients with acute leukemias. In this chapter, benign WBC and platelet disorders are reviewed.