[Towards better understanding of hematolymphoid malignancies--based on the WHO-2008 classification: summary].

The revised WHO classification of tumors of hematopoietic and lymphoid tissues (4th edition) was published in 2008. A number of information from molecular biology was introduced, new patterns of classification were proposed, and specific molecular diagnostics and molecular-targeting therapy were introduced in a part of these diseases. In this symposium, four remarkable points of the WHO-2008 classification (myeloproliferative neoplasms and JAK2 mutation, approaches to hypereosinophilic syndromes, morphology of myelodysplastic syndromes, and varied classification of lymphoid malignancies) were presented by the expert speakers, and the better understanding of the revised classification is warranted.