The Who Classification Of Leukemias

Harris et al.[1] reported the WHO classification of neo-plastic diseases of the hematopoietic and lymphoid tissues in 1999. This system modifies and incorporates the Revised European-American Lymphoma (REAL) clas-sification[2] and extends the principles underlying that schema to the classification of myeloid diseases. Like the REAL system, the WHO system attempts to classify neoplastic lymphohematopoietic diseases into discrete entities with unique clinico-biological features. In this way, the WHO classification is a conceptual improvement over the FAB classification,1-3-6-1 which primarily relied on morphological criteria.

To divide the lymphohematopoietic neoplasms into clinically relevant and biologically discrete entities, multiple diagnostic modalities are employed in the WHO system, including morphology, immunophenotype, clinical history, and cytogenetic abnormalities. With respect to cytogenetic and fluorescent in situ hybridization (FISH) evaluations of AML, the WHO classification has significantly upgraded the role of these modalities in diagnosis, prognosis, and relevance to treatment decisions. Within the acute leukemias, the major WHO categories include therapy-related AML-MDS, AML with multi-lineage dysplasia, and AMLs with recurrent cytogenetic translocations in addition to AML not otherwise catego-rized.[1] Thus cytogenetic data define one major group of AMLs. The delineation of specific cytogenetic diseases owes much to studies showing that cytogenetics could predict response to therapy[7-11] and therefore could be used to make treatment decisions.[7,12]

Fig. 1 Selected examples of specific chromosomal rearrangements associated with different AML subtypes. (From Ref. [18].)

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Getting Started With Dumbbells

Getting Started With Dumbbells

The use of dumbbells gives you a much more comprehensive strengthening effect because the workout engages your stabilizer muscles, in addition to the muscle you may be pin-pointing. Without all of the belts and artificial stabilizers of a machine, you also engage your core muscles, which are your body's natural stabilizers.

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