Molecular diagnosis of lymphomas and associated diseases

The aim of this review is to explore some of the major ways in which the techniques of molecular biology are affecting individual patient diagnosis with respect to lymphoproliferative disorders. The main impact in this particular sphere has been through the polymerase chain reaction which has enabled clonal analysis, the detection of diagnostically and prognostically important chromosomal abnormalities and the monitoring of therapeutic intervention via the detection of residual disease. This allows increased diagnostic accuracy and enables better targeting of therapeutic intervention. A younger technology, but none the less one with great diagnostic potential, is that of fluorescence in situ hybridisation which has bridged the gap between conventional cytogenetics, with its reliance on living tissues and its relative insensitivity in picking up chromosomal abnormalities, and molecular biology which forsakes morphology and which, in the shape of PCR at least, deals with relatively minute segments of the genome. The main techniques of clonal analysis are compared and contrasted and the usefulness of the detection of some of the major chromosomal abnormalities is discussed. The place of fluorescence in situ hybridisation is also elaborated. The major advantages and disadvantages of each of these techniques are described and their place in the scheme of diagnosis and treatment is briefly elucidated.