Therapy-related leukemia is a neoplastic hematopoietic disorder arising in most cases from a multipotent stem cell and in a few cases from a lineage-committed progenitor. Therapy-related acute myeloid leukemia (t-AML) describes a clinical syndrome that exhibits important differences from AML that arises de novo [1]. The terms "therapy-related" or "treatment-related" leukemia are descriptive and are based on a patient's history of exposure to cytotoxic agents. They imply a causal relationship, but the mechanism of this transformation remains to be established. These terms may ultimately be too restrictive, since the leukemia that develops after exposure to benzene or atomic bomb irradiation is very similar or identical to the therapy-related leukemia syndrome. In the future, as various subtypes of leukemia are distinguished by specific genetic alterations, the terms "de novo" (or primary) and "therapy- related" leukemia will likely be discarded and specific etiologies will be incorporated into the diagnostic nomenclature.
Keywords: MLL gene; Secondary leukemia; del 5; monosomy 5; monosomy 7.