[Cytoimmunofluorometry in the diagnosis of MALT lymphoma of the gastrointestinal tract].

MALT lymphoma is raised from lymphoid cells of mucosa associated lymphoid tissues in a long-term, multistep process of the accumulation of genomic damage very often under the influence of chronic (e.g. Helicobacter pylori) infection. Cytoimmunofluorometric analysis of cell suspensions obtained from mechanically disintegrated bioptic samples of gut mucosa is a very useful approach to detect the presence of MALT lymphoma cells. MALT lymphoma cells are in a great majority of B cell origin. Malignant cells are characterized by the typical characteristic SS parameter, strong expression of CD20 and CD79b molecules, and by the absence of CD5 and CD23 molecules. The ultimate evidence of clonality is immunoglobulin light chains either kappa or lambda expression determination.