Chronic lymphoproliferative disorders: an integrated point of view for the differential diagnosis.

Morphology is regarded as the principle basis for the identification of lymphoid neoplasms. Sometimes, however, it fails to discriminate among several chronic lymphoproliferative disorders (CLDs). Improved immunophenotyping has resulted in a better characterization of a number of variants of these diseases, some of which may benefit from different therapeutic approaches. In particular, the proposal of scoring systems using a panel of monoclonal antibodies (MoAbs) has represented a critical step in this field. In fact, to date, some MoAbs (CD5, CD23, FMC7, CD22, CD79b, and surface immunoglobulin density) are able to distinguish among several entities, thus allowing for a correct diagnosis in the majority of cases. However, there is still a small percentage of patients where the combined diagnostic approach (morphology and immunophenotyping) should be further refined by other techniques, such as cytogenetic and molecular characterization. Here numerous questions are raised indicating the need to more accurately differentiate the disease entities under discussion and better understand some of their clinical manifestations.