[B-cell lymphomas].

Among the hematologic tumors, lymphoid malignancies, especially B-cell lymphomas (BLs), are categorized according to the WHO classification into a large number of entities, which are aggregates of clinically and biologically diverse diseases. It is thought that various molecular genetic abnormalities are involved in lymphoid tumorigenesis. Recent advances in genetic analysis technology have resulted in the discovery of many novel and recurrent genetic abnormalities. In particular, those associated with diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), and mantle cell lymphoma have been identified utilizing molecular pathology techniques, which is important aspect for the future development of novel therapeutic drugs and indications for clinical trials. In this section, the possibility of patient-stratification based on genetic abnormalities of DLBCL and FL, which are particularly prevalent among mature BLs, are described. I also introduce the genetic features and clinical importance of BL and MCL identified in a small number of patients in Japan.