Hematopathology approaches to diagnosis and prognosis of indolent B-cell lymphomas

The advent of new technologies has contributed to improvements in the diagnosis and classification of the non-Hodgkin lymphomas (NHL). Use of a more extensive test menu of paraffin active monoclonal antibodies for immunohistochemistry, molecular cytogenetic studies including standard cytogenetics, multi-color fluorescence in-situ hybridization (FISH), polymerase chain reaction and locus-specific FISH, as well as developments in high-resolution techniques including microarray gene expression profiling and array comparative genomic hybridization (CGH) allow more accurate diagnosis and precise definition of biomarkers of value in risk stratification. The identification of disease-specific gene lists resulting from expression profiling provides a number of potential protein targets that can be validated using immunohistochemistry. We will highlight how improvements in our understanding of lymphoma biology rapidly facilitate the development of new diagnostic reagents that could be used to alter clinical practice. These changing trends allow the development of new diagnostic strategies used to render accurate sub-classification of entities within the category of indolent B-cell lymphomas, including their distinction from related but more aggressive disorders, such as mantle cell lymphoma. A comprehensive understanding of the biology of these distinct lymphoid tumors will allow us to identify novel disease-related genes and should facilitate the development of improved diagnostics, outcome prediction, and personalized approaches to treatment.