Leukemias

Leukemias represent a heterogeneous group of hematological malignancies. They arise as a result of cellular misadventures in blood-forming cells or lymphocytes, aberrations of normal cell processes, such as spontaneous mutations resulting in oncogene formation, and inadequacies of DNA repair mechanisms. However, exogenous factors, such as chemicals (benzene and components of cigarette smoke) and infections with micro-organisms, may also be involved in the development of leukemias (Lichtman 2008).